bissett 1991

A revision of the genus Trichoderma. 111. Section Pachybasium

JOHN BISSETT Biosystetnntics Research Centre, Agricult~ire Canncia, Research Branch, Central Esperitnet~tal Farm,

Ottnrva, Otlt., Cntzacia KIA OC6

Received February 25, 1991

BISSETT, J . 1991. A revision of the genus Trichocierma. 111. Section Pachybasium. Can. J . Bot. 69: 2373-2417 Twenty species assigned to Trichociermn section Pnchybasiutn (Sacc.) Bissett are described and diffcrcntiated on the basis

of conidiophore and conidium morphology. Included in section Pachybnsium are T. hntnntutn, T . polysl~orutn, T. pil~~lifer~itn, T. harziatlutn, and T. virens that were already recognized in Trichociermn; T . flavofuscutn comb.nov. transferred from Glio- claciiurn; the anamorphs of Hypocrea gelatinosn, H. semiorbis, and two unnamed Hypoo-ea species; and 10 new species segregated from the T. harnarutn species aggregate of M. A . Rifai (1969. Mycol. Pap. 116: 1-56). The new species Tri- chodertna crassutn, T . croceutn, T . fasciculatum, T . fertile, T . lotzgipilis, T . mitzutisporutn, T . oblotzgisporutn, T . pubescens, T . spirale, T . strictipilis, T . strigosum, and T . totnetrtosutn are proposed. Keys are provided to distinguish the 20 known species in section Pachybasiutn.

Key ~vorcis: Trichocienna section Pachybasium, Hypocrea, taxonomy.

BISSETT, J . 1991. A revision of the genus Trichoderma. 111. Section Pachybasium. Can. J . Bot. 69 : 2373-2417. L'auteur dCcrit et diffkrencie vingt espkces attribuies B Tricl~ociertna section Pachybasi~inl (Sacc.) Bissett sur la base de

la morphologie du conidiophore et de la conidie. I1 rCunit dans la section Pnchybasiutn le T. hnmarur?~, le T. polys~~orvm, le T. pilul$errim, le T. hnrzinnurn et le T. virerls qui sont dCjB reconnus comme Trichocierma; le T . flavofuscutn comb.nov. est transferre du genre Glioclaciiurn; les anamorphes de I'Hypocrea gelarir~osa, de I'H. setniorbis et de deux espkces d'Hy- pocrea provisoirement sans nom et 10 nouvelles espkces sont sCparCes de I'agrCgat d'espkces T. harnatum selon M. A. Rifai (1969. Mycol Pap. 116: 1-56). Les nouvelles espkces Trichoderma crassutn, T . croceutn, T . fasciculatum, T . fertile, T . lotzgipilis, T . tnitrutisporum, T . oblotzgispor~~tn, T . pubescens, T . spirale, T . strictipilis, T . strigosum, et T . tomentosum sont proposCes. L'auteur fournit des cl&s pour distinguer les 20 espkces connues de la section Pachybasi~irn.

Mors ciis : Trichociernza section Pachgbasiurn. Hypocrea, taxonomie. [Traduit par la redaction]

Introduction cxhibit characters that allow identification. The characteristic

Trichodermn section Pnchybasiiim was erected by Bissett (1991) to accommodate morphologically similar forms in the T . hamntiim, T . polysporum, T . piliiliferum, and T . harzianum species aggregates of Rifai (1969). The section was based on Pachybasiiim Saccardo (1 885), originally proposed to accommodate T . hamatum and T . polysporum, although Saccardo's concept was broadened to include related forms lacking a sterile elongation of the conidiophore main axis.

Species in Trichoderma section Pachybnsiunz are characterized by broad or inflated conidiophore elements and phialides, which give the conidiophore a stout or rigid appearance. The phialides are typically ampulliform, divergent, and arranged in crowded verticils on terminal branches of conidiophore that are repeatedly branched and rebranched at an indefinate num- ber of levels. The majority of the species in section Pachy- basiiim have conidiophores aggregated in compact, flat to hemispherical pustules. In addition, many species have conspicuous, sterile elongations of the conidiophore main axis, which is a feature unique to section Pachybasium.

The present contribution provides names for common wood- and soil-inhabiting strains referable to Trichoderma section Pachybasium. Doi and Doi (1986) listed specific epithets that have been proposed for Trichoderma Pers.:Fr., and for the synonyms Pachybasium Sacc. and Pyrenium Tode. These ear- lier epithets are adopted when the original description or type specimen allows the determination of the identity of the species. However, the specific nature of most of these taxa cannot be determined on the basis of their original descriptions. Fur- thermore, many type specimens cannot be located (e.g., Doi and Doi 1986), and the few available types usually do not

conidiophore structure is lost in herbarium specimens, with branches and phialides seceding or breaking-off from the conidiophore main axis.

The anamorphs of more than 60 species of Hypocrea (Fr.) Fr. were described by Doi (1966, 1967, 1968, 1969, 197 1, 1972, 19730, 1973b, 1974, 1975a, 1975b, 1976, 1978). Liv- ing cultures are not available for most of these anamorphs, and most cannot be accurately placed in the taxonomic system pre- sented here. The Trichoderma species most often isolated from natural substrates could not be correlated with Hypocrea anamorphs, and it is possible that teleomorphs do not exist for many of these species. However, four Hypocrea anamorphs that show a morphological affinity to wood- or soil-inhabiting species in section Pachybnsium are described from ascospore cultures.

Differentiation of species in section Pachybasiu~n

The branching pattern and morphology of macronematous conidiophores are the main characters used to distinguish species in the present study. In the majority of the species, which produce compact, hemispherical conidiogenous pustules, the conidiophores arise from a few, broad hyphae that branch extensively near the surface of the substrate prior to the production of fertile branches. These conidiophores produce fertile branches in verticils at regular intervals, with the branches decreasing in length toward the conidiophore apex and usually rebranched several times, forming a more or less pyramidal structure. Adjacent conidiophores frequently anastomose in the apical region. Other species form more loosely organized, flat pustules or irregular fascicles, and have more numerous conid-

Primed in Canada i JmprimC au Canada

iophores arising in proximity from the substance. The conidiophores of these species are frequently unbranched at the base, and sparingly branched throughout the fertile part. with the branches relatively short or more or less uniform in length. resulting in a more linear arrangement of the conidiophore. The anastomosis of adjacent conidiophores is less frequent or absent in the latter species.

The morphology of the mature conidiophore apex distin- guishes species that have the conidiophore main axis branched and fertile to the apex from species with sterile apical elongations of the conidiophore. This character influences colony characteristics such as the colour and surface texture of the conidiogenous pustules. The width, length, branching, and shape or linearity of the sterile conidiophore elongations are useful characters for distinguishing species that are otherwise similar and probably closely related.

Conidium size, shape, and colour also are useful for identification. Two species are readily differentiated in having colourless conidia. Conidium pigments in the other species vary from grey, to brown, or pale to dark green. Conidium shape may be subglobose, obovoid, oblong to short cylindrical. or narrowly to broadly ellipsoidal. Conidia of all species cur- rentIy accommodated in section Pacl~ybasirrm appear smooth- walled in light microscope observations. However, a few species have minutely rugose or verruculose conidia visible only in electron microsco~e observations.

Several morphologically related groups of species are apparent among the twenty species assigned to section Pnchy- basium. Three species have relatively broad conidiophores that are sparingly branched and loosely organized into flat pustules, or predominantly effused. Conidia in these three species are large and broadly ellipsoidal to obovoid. Of the three species sharing these characteristics, T . virens (Miller et al.) Arx is distinguished by having entirely effuse conidiation, conidiophores lacking a sterile elongation, and dark green conidia. T. crassum sp.nov. has conidiophores aggregated into flat pustules and with conspicuous, sterile, apical elongations, and dark green conidia. Trichoclerma flnvofuscrcm (Miller et al.) comb.nov. has conidiophores aggregated into flat pustules and lacking apical elongations, and brown conidia. The Tricho- dertna anamorph of Hypocrecr gelntinosn (Tode:Fr.) Fr. has similar large conidia and irregularly branched conidiophores, but differs from the above three soecies in having the conid- " iophores unbranched near the baie, and thereafter h e a r in structure, with usually paired, fertile branches not varying in length arising at acute angles toward the apex, and Glioclad- ium-like verticils of appressed branches and phialides near the apex. Based on published descriptions (Do1 1971, 1972, 1973b; Samuels et al. I990), the Trichocler7nn anamorphs of Hypocrea argillacen Phil. & Plowr., H. sublirteu Doi, and H. luteo-viretzs Doi appear morphologically similar to the above species. Along with H. gelcrtinosa, all are referable to Hypocrea subsection Creopus (Link) Doi. The anamorph of

I

H. psychrophila Miiller et al. (Miiller et al. 1972) also has a similar conidiophore morphology, but with colourless conidia. Anamorphs of these species of Hypoereti were not available for examination in the-current study.

The majority of the species in section Ptrchybcrsiun~ produce compact, nearly hemispherical conidiogenous pustules with characteristic, sterile, conidiophore elongations. Of these, three species are allied in having verticillate conidiophore elements of moderate dimensions and narrowly ellipsoid conidia also of moderate size. Trichodermn hunlaticm (Bon.) Bainer is

distinguished by the strongly undulate to hamate conicliophore apex. giving the conidiogenous pi~stules a velvety appearance. Tt.ichorler111lr puhe,scrr~.s sp.nov. has t h i n , highly ramified, undulate apices. and pustules with a downy surface texture. ~ ~ ~ i ~ ~ h o r l c r r ~ c r srrigosrrr;r sp.nov. has straight. javelin-like apices that impart a spiny appearance to the pusti~les. Two other species show affinity to this group. but have shorter, broadly ellipsoidal conidia and less ramified conidiophores giving rise to smaller, less compact pustules or fiiscicles. In T. .sfric.til)ili.s sp.nov., conidiophores are aggregated into small pustules. and the conidiophore apex is relatively long and straight or slightly flexuous. giving the pustules a hairy appearance. In T. firscic.rrlorlirn sp.nov.. conidiophores are aggregated into loose fascicles, and the Ikitter species also is characterized by remarkably narrow aerial hyphae and small chlamydospores.

Two species produce compact pustules but have conidia that appear greyish or pale green microscopically. Conidia are larger than in the T. htrrr~ot~~rr~ group. and oblong to more or less cylindrical. In T. ol~lo~lgi.sl)orrr~rl sp.nov. the conidiophore apex is relatively straight and unbranched. In T. lo11gi~)ili.s sp.nov. the apex is strongly undulate and highly ramified. A third species. the Trichorlertrrn nnamorph of H!pocrc~tr s~111io1.- bis Berk., shows affinity in having relatively long. grey-green conidia, but conidia in this species tend to be ellipsoidal rather than parallel-sided. In addition, the conidiophore main axis is less branched and wider over the fertile part in the latter species. Pnchybnsirlrn r~rric,oln Kamyshko (1961) also has relatively large, pale green conidia; however, material of this species was not located for study.

Two species have conidiophore main axes that are particularly broad and rigid toward the apex, with conidia smaller than in the T . ha~tzorrrrn group. These two species also produce distinctive bright yellow or reddish piginents in the colony reverse. Tric.hoclernza fertile sp.nov. has straight conidiophore elongations with a few, short, fertile branches near the apex whereas T. spirnle sp.nov. has spiral conidiophore elongations that are unbranched and nonfertile to the apex.

Trichoclermn mi~~rrrisporrr~n sp.nov. and T. rometzio.srr~n sp.nov. have highly branched conidiophores aggregated in compact pustules and relatively small, ellipsoidal conidia. Tri- choclermtr ~,zirlirfisporrr~rz has conidiophores branched and fertile to the apex. The conidiophores are aggregated into flat. speading yellow-green pustules that appear mealy owing to the dense conidiation. Tric,hodennn tolnentosrr~n has conidiophores with a conspicuous coiled or circinate conidiophore elongation and aggregated into snialler, compact, bluish green ~ustules.

The remaining species show limited morphological affinity to each other or to the previous species. Trichoclermn poly- sporiun (Link:Fr.) Rifai and T. pilulij'rrr~r~ Webster and RiPai have hyaline conidia that appear white in mass. However, T. polysporrrnz has much broader conidiophores and branches, and sterile conidiophore elongations that are absent in T. piluliferum. Conidia of the two species also differ in shape. Trichodermn croceicm sp.nov. resembles T. poly.spor~cn1 in some respects. Both species have coiled, tuberculate, sterile conidiophore elongations, but conidiophores and branches are narrower in T. croceicm. The latter species also has larger, green rather than colourless conidia. Trichodertrrrr harzinnurn Rifai has conidiophores that are branched and fertile to the apex and lacking a sterile elongation. In this respect, and in having small, globose conidia, the latter species resembles T. pilulifer~rttz. Trichodermn hcrrzinnutn differs in having green

conidiation with conidiophores predominantly effused or vations on malt agar (MA). unless otherwise specified as potato aggregated in loose. flat pustules . dextrose agar (PDA). Blakeslee's agar (BLA). or Czapek Dox

Cultural conditions for the descriptions that follow were agar (CDA) . Colour terms are from Ridgway (1912). with given by Bissett (1984) . The descriptions are based on obser- Ridgway plate numbers in parentheses .

Dichotomous key to species in Trichoderma section Pachybasium 1 . Conidiation entirely effuse. or conidiophores arranged in loosely organized flat pustules or small irregular fascicles; conidio-

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . phores sparingly branched with principal branches most often arising singly or paired 2 I . Conidiophores organized in compact. hemispherical to cushion-shaped pustules on MA; conidiophores usually highly branched

with branches 2-4 verticillate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 . Conidiophores arranged in fascicles up to 2 mm in diameter . . . . . . . . 2 . Conidiophores effuse. or loosely arranged in flat pustules . . . . . . . . . . .

3 . Colonies less than 4 cm in diameter after 4 days at 20°C; aerial hyphae more than 1.5 Fm in diameter; chlamydospores infrequent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trichodermcl anam . H . g~lat ir~osc~ (6)

3 . Colonies more than 4 cm in diameter after 4 days; aerial hyphae mostly less than 1.5 Fm in diameter; chlamydospores abundant in older mycelium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T . fa.sciculat~or~ (3)

4 . Conidia subglobose to obovoid. smaller than 3.5 X 2.5 ~m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 . Conidia broadly ellipsoidal, larger than 3.5 x 2.5 ~m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 . Conidia pale brown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 . Conidia dark green . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6 . Conidiophores aggregated into flat pustules on MA. usually with sterile apical elongations . . . . . . . . . . . . . . . . . . T . crassurn (1) 6 . Conidiation entirely effuse. or conidiophores lacking sterile apical elongations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T . virerzs (20)

7 . Conidiation white to buff . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 7 . Conidiation eventually green to grey . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Conidiophore with spiral. sterile apical elongations; conidia ellipsoidal T . pol~~sporum (1 3) I 8 . Conidiophores lacking sterile elongations; conidia subglobose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T. piluliferurn (12)

9 . Conidiophores with conspicuously roughened. spiral. sterile apical elongations; conidiation bright greenish yellow or rosy-buff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T croceum (2)

. . . . . . 9 . Conidiophores lacking sterile elongations or elongations not roughened; conidiation in various green or grey shades 10

10 . Conidiophores arranged in pustules up to 2 mm in diameter. glaucous to greyish; and conidiophore main axis 4.5-7 Fm wide over the fertile part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trichodermu anam . H . semiorbis (15)

10 . Conidiophore pustules larger, usually in definite green shades; or conidiophore main axis not exceeding 5.5 Fm wide over the fertile part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I I

l l . Conidia consistently less than 3.5 Fin long and 2.5 ~m wide . . . . 1 1 . Conidia mostly longer and (or) wider . . . . . . . . . . . . . . . . . . . . . . . . . .

12 . Conidia subglobose to broadly obovoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 . Conldla ell~pso~dal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . 13 . Conidiogenous area bright green to yellow.green. conidiophore main axis branched and fertile to apex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T rr~it~utisporurn ( 10)

13 . Conidiogenous area grey.green. conidiophore main axis with conspicuous spiral sterile apical elongations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T ~or~~erz~osum (19)

14 . Colony reverse conspicuously pigmented yellow to reddish brown shades; conidiophore main axis very stout. 4-6.5 km wide at base of sterile elongation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I5

14 . Colony reverse colourless to pale dull yellowish; conidiophore main axis usually 3.5-5 Fm wide at base of sterile elongation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

15 . Conidiophore main axis relatively straight throughout. the upper part unbranched and nonfertile to near the apex. that is ter- . minated by a single phialide or more often by 2-3 short fertile branches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T ferlile (4)

15 . Conidiophore main axis with a spiral. sterile apical elongation. never with fertile branches near the apex . . . . . T . spirale (16)

16 . Conidia frequently longer than 4.5 ~ m . never shorter than 3.5 ~m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 16 . Conidia rarely longer than 4.5 ~ m . often shorter than 3.5 ~m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

17 . Conidiophore main axis with undulate to spiral sterile elongation that is highly branched and anastomosing to within 100 Fm of the acute apex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T . Iongipilis (9)

17 . Conidiophore main axis with a straight to flexuous sterile elongation that is sparingly branched with a bluntly rounded apex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T. oblor~gispor~[tn (I I)

18 . Conidiophore main axis with straight to flexuous sterile elongation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 18 . Conidiophore main axis with undulate to coiled or circinate. sterile elongation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

19 . Conidiogenous pustules bluish green. appearing spiny owing to presence of stiff. javelin-like sterile conidiophore apices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T . strigosutn (18)

2376 CAN . J . BOT . VOL . 69. 1991

19 . Conidiogenous pustules dull green. appearing hairy owing to presence of very long. straight or flexuous sterile conidiophore . . apices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T . str~ct~pilis (17)

20 . Conidiogenous pustules bluish green. appearing velvety owing to presence of strongly undulate or hamate. sterile conidiophore apices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T . /zatnatutn (7)

20 . Conidiogenous pustules bright green. surface appearing downy owing to presence of branched. undulate. thin. sterile conidiophore apices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T . pubescet~s (14)

20 . Conidiogenous pustules bluish green . appearing woolly owing to presence of coarse. spiral. conidiophore apices . . . . . . . . . . . . T spirrlle (16) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Synoptic key

Mycelium Species No.'

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (a) Aerial hyphae up to 1.5 pm in diameter 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (b) Aerial hyphae exceeding 1.5 pm in diameter .1,2, 4-20

Chlamydospores (a) Lacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.6. 9 (b) Small (< 10 pm in diameter). wall < 1 pm wide . . . . . . . . . . . . . . . . . . . . . . . .2.3.6.8.10-13.16.17. 19 (c) Large (> 10 pm in diameter). wall > 1 pm wide . . . . . . . . . . . . . . . . . . . . . . . .1.4.5.7.8.14-16.1 8-20

Conidiation (a) Effuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5.8.12.15. 20 (6) Spreading. flat pustules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5.8. 10 (c) Small fascicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.6. 12 (rf) Compact. hemispherical pustules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.4.7-9.11.1 3-19

Sterile apical elongations (at maturity) Shape

(a) Lacking sterile elongations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.5.6.8.10.12. 20 (b) Straight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.4.11.15.17. 18 (c) Flexuous. undulate. circinate or hamate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.7.9.11.14. 15 (rf) Coiled or spiral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.13.16. 19

Ornamentation (a) Tuberculate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2. 13 (b) Smooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.4.7.9.11.1 3-19

Conidia Colour in mass

(a) White . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l2 . 13 (b) Grey to grey-green . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9.11. 15 (c) Bright to dark green . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .l-4.6-8.10.14. 16-20 (d) Brown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Shape (a) Subglobose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8. 12

. . . . . . (b) Obovoid to broadly ellipsoid. maximum size exceeding 4 X 3 pm .1.5.6. 20 (c) Ellipsoidal. maximum size not exceeding 4 X 3 pm . . . . . . . . . . . . . . . . . . . .2-4.6.7.10.1 3-19 (rf) Oblong to cylindrical. maximum length exceeding 4.5 pm . . . . . . . . . . . . . . .4.9.11. 15

Culture Growth rate (MA. 20°C. 4 d)

(a) Rapid (> 6.5 cm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3-5.7-11.14.16.19. 20 (b) Moderate (5-6.5 cm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.3.7.1 3- 15.1 7- 19 (c) Slow (< 5 cm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.12. 15

Reverse pigment (PDA) (a) Colourless to buff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.7.8-13.1 6-18 (b) Dull yellowish to amber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.3.5.6.8.1 0- 15.1 8-20 (c) Bright yellow. or greenish to reddish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.10. 16

'These numbers refer to the 20 species that are described following this key .

1 . Trichoderma crassum sp.nov. Figs . 1-8 Coloniae celeriter crescentes. 5-6.5 crn diarnetro post 3 dies

(20°C). rnycelio floccoso cinerascente. reverso fulvo . Partes conidiiferae effusae glauco-griseus aut pustules applanatas atrovirides usque ad 10 rnrn diarnetro facientes . Hyphae hyalinae leves plemrnque 1.5-9 prn latae . Chlarnydosporae abundantes solitariae intercalares vel terrninales leves subhyalinae vel viridulae subglobosae vel ellipsoideae vel pyriforrnes 6- 17 prn diarnetro . Conidiophora hyalina levia simplicia aut in

pustulis irregulariter rarnosa crassa recta base usque ad 7 Krn lata pro parte rnajore 3.5-5.5 prn lata. rarnis principalibus solitariis aut 2-3 verticillatis ad apicem conidiophorae curvatis ad basirn conidiophorae elongatis. ad apicern fere recta per usque ad 150 Krn nonrarnosa. apice sterilia aut phialide singulari au raro 2-3 phialidibus verticillatis . Phialides in pustulis arnpulliforrnes 4.4-9.5 x 3.0-4.2 prn plerurnque 2-5 verticillatae ad apicern conidiophorae curvatae adpressae. phialides in partibus conidiiferibus effusis arnpulliforrnes vel lageni-

formes vel subulatae usque ad 30 pm long. Conidia atroviridia levia late ellipsoidea plerumque 3.7-5.3 x 2.6-3.7 pm saepe in capitulis magnis mucosis connexa.

TYPUS e solo sub Piceae excelsiae isolatus, "Lacolle, QuC- bec, Canada", leg. P. Widden, 1V. 1976, DAOM 164916 (pro cultura exsiccata).

Colonies growing very rapidly, 5-6.5 cm in diameter after 3 days; aerial mycelium floccose to woolly, greyish. Conidia- tion abundant, effuse, or aggregated in compact, flat pustules up to 10 mm diameter on MA (Fig. 2); effuse conidiation dull greenish, from sage green (XLVII) to nickel green (XXXIII); pustules quickly turning dark green shades from dark terre verte (XXXIII) to dusky dull green (XLII), slate olive, or dull greenish black (XLVII). Exudate pale yellowish, in small droplets in the aerial mycelium on PDA. Reverse colourless or slowly turning dull yellowish to amber shades. Odour indistinct. Hyphae hyaline, smooth-walled, or with occasional, irregular wall thickenings; aerial hyphae mostly 1.5-9 pm in diameter, submerged mycelium up to 15 pm wide. Chlamydospores very abundant, in young cultures predominately terminal on short branches of the aerial mycelium, later intercalary or terminal (Fig. 7), solitary, subglobose to ellipsoidal or pyriform, 6- 17 pm in diameter, subhyaline to pale greenish, wall smooth and up to 1 pm thick, contents appearing coarsely granular in some isolates. Conidiophores hyaline, smooth-walled; in areas of effuse conidiation phialides arising singly or in whorls of 2-4 on prostrate, undifferentiated hyphae, or on short, lateral branches from the aerial mycelium (Fig. 6); macronematous conidiophores in pustules coarse, straight, erect, up to 7 pm wide near the base, gradually tapering to 3.5-5.5 pm wide for most of their length; branching irregularly, primary branches arising at right angles, more or less curved toward the apex of the conidiophore, and increasing in length toward the base of the conidiophore, arising singly or in whorls of 2 or 3, rebranched once or twice; ultimate branches mostly 1-celled, cylindrical, 6-14 x 3.5-5 pm; the apical part of the main conidiophore axis is straight or slightly flexuous, sterile and unbranched for up to 150 pm to the apex (Fig. l ) , anastomosing occasionally with adjacent conidiophores, occasionally branching once or twice just above the fertile part, tapering gradually from 3.5-5 pm diameter to about 1.5 pm in diameter at the bluntly rounded apex; distinctly septate, with septa 15-45 pm apart, more closely septate toward the apex; the apex is persistently sterile, or in older cultures the apex may be modified into a single, more or less subulate phialide up to 20 km long, rarely with a terminal whorl of 2 or 3 phialides. Phialides from macronematous conidiophores ampulliform (Figs. 4, 5), mostly 4.4-9.5 x 3.0-4.2 pm, constricted at the base, abruptly constricted to a broad tip about 1.2 pm wide, mostly arising in crowded whorls of 2-5 on terminal branches, occasionally arising in whorls laterally on the conidiophore and its branches, rarely solitary; usually reflexed toward the apex of the conidiophore and appressed rather than divergent; phialides from undifferentiated hyphae in areas of effuse conidiation ampulliform to lageniform or subulate, lateral phialides up to 20 pm long x 2.5-4 pm wide, terminal phialides up to 30 pm long; attached very broadly to the conidia with the apex up to 3 pm wide. Conidia broadly ellipsoidal (Fig. 8), mostly 3.7-5.3 x 2.6-3.7 pm (avg. 4.3 X

3.0 pm), slightly larger and occasionally obovoid from areas of effuse conidiation, both ends broadly rounded or the base slightly narrower, smooth-walled, dark green.

FIG. I. Trichoder~nu crassum. Conidiophore ( x 750) and conidia ( x 1500). DAOM 164916. Type isolate.

MATERIAL EXAMINED: CANADA: ONTARIO: near Longlac, soil, V. 1984, M. T. Dumas (DAOM 199078); Nepean, Thiljn occidelltalis L. log on ground, 3.1V.1980, N. Grainger (DAOM 175925); Ottawa, isolated from Gypsy moth egg mass, XII. 1984, M. 1. Timonin (DAOM 191330); QUEBEC: Lacolle, spruce forest soil, IV. 1977, P. Widden (DAOM 167076, 167077); soil in Norway Spruce plantation, V. 1977, P. W. (DAOM 1649 13, 164914, 164916 TYPE culture); spruce forest soil, VI. 1977, P. W. (DAOM 167055; 167063). UNITED STATES: OREGON: Pringle Falls Experimental For- est near Bend, isolated from burnt soil, 1983. J . Reaves (DAOM 196544); Rainier, decayed roots of Pseudotsuga menziesii, E. Nelson (DAOM 195 135, 195 136, 195 137).

NOTES: This species appears closely related to T. virens. The morphology of phialides and conidia arising from undifferentiated hyphae in effuse areas of conidiation is similar in the two species. Both species have broad, irregularly branched conidiophores and relatively large dark green conidia. HOW- ever, the macronematous conidiophores in T. clnssuln are more complexly branched and organized into conspicuous flat pustules. These conidiophores frequently have a sterile apical elongation that is lacking in T. virens, and conidia produced

2378 CAN. J . BOT VOL. 69. 1991

FIGS. 2-8. Trichorlenna onssum. Fig. 2. Flat. spreading conidiogenous pustule on MA aftcr 12 d . x 3. Scale bar = 2 pm. Fig. 3. Straight. sterile conidiophore elongations. x 200. Scale bar = 20 km. Figs. 4 and 5. Conidiophore branches with relatively largc. a~npulliform phialides often bent toward the conidiophore apex. x 1250. Scale bars = 5 pm. Fig. 6. Appressed phialides on micronernatous conidiophore with conidia coalescing into a single large head. x 1250. Scale bar = 5 pm. Fig. 7. Hyaline chlamydospores from submerged mycelium. x600. Scale bar = 10 pm. Fig. 8. Large, broadly ellipsoid to obovoid conidia. x 1250. Scale bar = 5 pm. Figs. 2. 3. and 7. DAOM 164913. Fig. 4. DAOM 167076. Figs. 5 and 8. DAOM 164914. Fig. 6. DAOM 167077. Figs. 3-8. Interference contrast.

from the macronematous conidiophores are narrower, tending to be broadly ellipsoidal rather than obovoid. Trichodermafla- vofuscum also has a similar conidiophore morphology, but is readily distinguished in having brown conidia. The conidiophore in the latter species is always branched and fertile to the apex.

2. Trichoderma croceurn sp. nov. Figs. 9-17 Coloniae circa 5 cm diametro post 4 dies (20"C), mycelio

lanoso cinerascente, reverso cremicolori. Partes conidiiferae pustulas numerosas compactas flavovirentes plerumque minus quam 3 mm diametro facientes. Hyphae hyalinae leves 1.5- 7 p,m latae. Chlamydosporae paucae solitariae terminales vel intercalares leves subhyalinae subglobosae vel ellipsoideae vel pyriformes 3-7 p,m diametro. Conidiophora hyalina levia praeter apicem aspemm sinuolata regulatim ramosa base usque ad 7.5 p,m lata pro parte majore 4-6 p,m lata, ramis 2-3 verticillatis ad basim conidiophorae elongatis, apice spiralis sterilis per usque ad 150 p,m nonramosa demum aspera. Phialides 2-5 verticillatae ampulliformes plerumque 4.0-6.8 x 2.6- 3.8 p,m. Conidia subhyalina levia late ellipsoidea 2.8-4.0 x 1.8-2.5 p,m.

TYPUS e solo sub Pino sp. isolatus "Lacolle, Qukbec, Canada," P. Widden leg., V. 1975, DAOM 167068 (pro cultura exsiccata).

Colonies growing moderately, about 5 cm in diameter after 4 days; aerial mycelium usually limited, or on PDA with white or greyish, woolly mycelium. Conidiation (Fig. 10) typically in numerous, compact, cushion-shaped to hemisphaerical pustules (especially MA), mostly less than 3 mm in diameter, but often concrescent to form irregular or concentric masses; white at first, rather slowly turning bright greenish yellow shades (never dark green) from yellowish glaucous to light grape green (XLI), or sea foam green (XXXI), glass green or Kildare green (XXXI); conidiation variable in colour in age, with large pustules (BLA) bright green near tea green (XLVII) to water green or mytho green (XLI), and small pustules (MLA) in pale rosy- buff shades from vinaceous buff to light drab (XL), or pustules may shade from green at the center to buff at the margin. Reverse colorless or pale buff. Exudate lacking. Odour indistinct. Hyphae hyaline, smooth-walled, 1.5-7 p,m in diameter. Chlamydospores few, developing in old cultures mostly in the submerged mycelium, terminal or intercalary, solitary, subhyaline, subglobose, ellipsoidal or pyriform, 3-7 p,m in diameter, smooth- and thin-walled (usually about 0.5 p,m thick), with contents appearing granular (Fig. 16). Conidiophores hyaline, smooth-walled except near the apex, main axis usually somewhat sinuous, 4-6 p,m wide for the most part but up to 7.5 p,m wide near the base, branching at right angles and at regular intervals; primary branches usually arising in whorls of 2 or 3, increasing in length toward the base of the conidiophore; secondary branches solitary or in whorls of 2 or 3, mostly 1- or 2-celled; terminal cells swollen and barrel-shaped to subglobose, mostly 5-9 x 3.5-5 p,m; the conidiophore apex is loosely spiraled (especially MA), nonfertile and unbranched for up to 150 p,m to the apex (Figs. 1 1, 12), sometimes branching once or twice just above the fertile part, tapering from about 3.5-5 p,m to about 1.5 p,m wide at the bluntly rounded apex, at maturity the nonfertile part is conspicuously roughened or tuberculate (Figs. 14, 15); septa are evenly and closely spaced, mostly 10- 18 p,m apart. Phialides ampulliform, mostly 4.0-6.8 x 2.6-3.8 p,m, more or less constricted at the base, narrowing abruptly to a short conidium-

F I G . 9 . Trichoderma croceum. Conidiophore ( x 750) and conidia ( x 1500). DAOM 167068. Type isolate.

bearing tube about 0.8 p,m wide; arising in whorls of 2-5, but mostly in uncrowded verticils of 2 or 3 (Fig. 13). Conidia broadly ellipsoidal (Fig. 17), both ends broadly rounded or the base slightly narrower, 2.8-4.0 x 1.8-2.5 p,m (avg. 3.2 x 2.2 p,m); smooth-walled, appearing thin-walled, subhyaline viewed singly, usually greenish yellow in mass.

MATERIAL EXAMINED: CANADA: QUEBEC: Lacolle, pine forest soil, V. 1975, P. Widden (DAOM 167068 TYPE culture).

NOTES: Trichoderma croceum is readily distinguished by the conspicuously roughened apical elongation of the conidiophore and bright greenish yellow or rosy-buff conidiogenous pustules. Morphologically this species most resembles T. polysporum, differing in the colour and size of the conidia, which are colourless and somewhat narrower in T. polysporum.

3. Trichoderma fasciculatum sp.nov. Figs. 18-21 Coloniae 5.5-7 cm diametro post 4 dies (20"C), mycelio

sparso floccoso cinerascente, reverso hyalino vel stramineo. Partes conidiferae pustulas parvas irregulares griseo-virides facientes. Hyphae hyaline leves plerumque 0.7-6.0 p,m latae raro usque ad 9 p,m parsaepe minus quam 1 p,m latae. Chla- mydosporae abundantes plemmque terminales solitariae in hyphis angustis infrequenter intercalares, hyalinae pariete tenui subglobosae vel pyriformes plemmque 2.5-6 p,m diametro. Conidiophora hyalina levia basi usque ad 7 p,m lata pro parte majore 3-5 p,m lata irregulariter et parce ramosa, ramis principalibus comparate longis solitariis aut 2-3 verticillatis, ramis secondariis dispersis, ad apicem angusta flexuosa nonramosa steriles, apice phialide singulari subulata aut verticillo phiali- dum lageniformium ferentia. Phialides lageniformes vel ampulliformes 4.2-7.8 x 2.2-3.5 p,m singulares aut 2-5 verticillatae, phialides terminales anguste lageniformes vel sub-

2380 CAN. J. BOT VOL. 69. 1991

FIGS. 10-17. Trichodennn croceutn. DAOM 167068. Type isolate. Fig. 10. Hemispherical conidiogenous pustules after 12 d on MA. X 3. Scale bar = 2 mm. Fig. 11. Strongly undulate, nonfertile conidiophore extensions. X 200. Scale bar = 20 Fm. Fig. 12. Coiled, tuberculate conidiophore extensions (SEM). x 425. Scale bar = 20 km. Fig. 13. Conidiophore showing regular dendroid branching and small ampulliform phialides. x 500. Scale bar = 10 Fm. Figs. 14 and 15. Tuberculate roughenings on conidiophore apex. Fig. 14. x 600. Scale bar = 10 Fm. Fig. 15. x 1250. Scale bar = 5 Fm. Fig. 16. Small subglobose chlamydospores in the submerged mycelium. x 600. Scale bar = 10 Fm. Fig. 17. Small, ellipsoidal conidia. x 1250. Scale bar = 5 Fm. Figs. 1 1 and 13-17. Interference contrast. Fig. 12. SEM on nonfixed, air- dried material.

F I G . IS. Trichoderma fasciculatum. Conidiophore ( x 750) and conidia ( X 1500). DAOM 167646. Type isolate.

ulatae usque ad 22 pm longae. Conidia viridula levia late ellipsoidea plemmque 2.9-4.0 X 2.0-2.9 pm.

TYPUS ex ascosporis Hypocreae sp. indet. in cortice Betulae sp. isolatus, "Vaals" Hollandia, J. Stalpers leg., XII. 197 1, DAOM 167646 (pro cultura exsiccata).

Colonies growing moderately rapidly, 5.5-7 cm in diameter after 4 days; aerial mycelium sparse, floccose, greyish. Conid- iation slow to develop, after about 10 days on malt agar forming small, irregular, evenly distributed fascicles up to 2 mm in diameter (Fig. 19); white at first, slowly turning dull green, from tea green or vetiver green to celandine green or pea green (XLVII). Reverse colourless or pale buff to yellowish. Exu- date lacking. Odour lacking or indistinct. Hyphae hyaline, smooth-walled, mostly 0.7-6.0 pm wide, submerged mycelium rarely up to 9 pm wide, aerial mycelium usually very narrow (less than 1.0 pm wide). Chlamydospores fairly abundant, usually terminal and solitary on narrow hyphae, infrequently intercalary; hyaline, thin-walled, subglobose to pyriform, mostly 2.5-6.0 pm in diameter; intercalary chlamydospores up to 9 x 7 pm. Conidiophores hyaline, smooth-walled, up to 7 pm wide near the base, gradually

tapering to 3-5 pm wide for most of their length; branching irregularly and somewhat sparingly, all branches arising more or less at right angles; primary branches relatively long (more than 150 pm) especially toward the base of the conidiophore, arising singly or more often in pairs or groups of three, rebranched irregularly; secondary branches uncrowded, 1- to 4-celled, all cells nearly cylindrical, terminal cells mostly 5- 12 x 2.5-4 pm; upper part of conidiophore main axis usually with a narrow, flexuous, unbranched, nonfertile part below the apex, the apical cell usually bearing a single, subulate phialide, or sometimes bearing a terminal verticil of lageniform phialides, less often the upper part of the conidiophore with sparse, irregular, fertile branching to the apex without a dis- tinct sterile part (Fig. 20), septa indistinct and relatively distant (up to 25 pm apart). Phialides mostly lageniform to ampulliform, 4.2-7.8 x 2.2-3.5 pm, usually constricted at the base, tapering to a narrow conidium-bearing tip about 0.7 pm wide, arising singly or in whorls of 2-5 (usually 2 or 3); terminal phialides narrowly lageniform to subulate and up to 22 pm long and 2-2.5 prn wide. Conidia broadly ellipsoidal (Fig. 21), both ends broadly rounded, mostly 2.9-4.0 x

2382 CAN. J . BOT VOL. 69. 1991

FIGS. 19-21. Trichoderma fasciculatum. DAOM 167646. Type isolate. Fig. 19. Conidiogenous fascicles on PDA after 12 d. x 3. Scale bar = 2 pm. Fig. 20. Upper portion of a conidiophore showing straight conidiophore extension. in this case with lageniform phialides near the apex. x 500. Scale bar = 10 pm. Fig. 21. Broadly ellipsoidal conidia. x 1250. Scale bar = 5 pm. Figs. 20 and 2 1. Interference contrast.

2.0-2.9 pm (avg. 3.4 x 2.3 pm), very rarely up to 6 x 3 pm; smooth-walled, greenish.

MATERIAL EXAMINED: NETHERLANDS: VAALS: isolated from ascospores of Hypocrea sp.indet., on Betula sp. bark, XII.1971, J. Stalpers (DAOM 167646 TYPE culture, ex CBS 118.72).

NOTES: The species is distinguished by the production of numerous, dull green conidiogenous fascicles less than 2 mm in diameter (Fig. 19). Aerial hyphae are unusually narrow, mostly less than 1 pm in diameter, and bear numerous terminal chlamydospores up to 6 pm in diameter on short lateral branches. Although lacking compact, hemispherical conidiogenous pustules, T. fasciculatum may be most closely related to the T. hamatum group of species, based on similar conidiophore morphology and branching patterns. Conidia are shorter than in T. hamatum sensu stricto, but close in size to those of T. strictipilis, which it most closely resembles.

4. Trichoderma fertile sp.nov. Figs. 22-3 1 Coloniae 6.5-8 cm diametro post 4 dies (20°C), mycelio

lanoso albo, reverso luteo. Partes conidiiferae typicae pustulas numerosas laxas applanatas vel pulvinatus flavovirentes usque ad 5 mm diametro facientes. Hyphae hyalinae vel subhyalinae leves aut raro indistincte asperulae plerumque 2-7 pm latae. Chlamydosporae paucae intercalares aut terminales leves subhyalinae vel viridulae plerumque ellipsoideae vel subglobosae 6-12 x 4-9 p m raro cylindricae usque ad 16 x 10 pm. Con- idiophora hyalina levia basi usque ad 8 p m lata pro parte majore 5-6.5 p m lata regulatim ramosa, ramis principalibus et secondariis brevibus 2-3 verticillatis, ad apicem rigida recta per usque ad 120 pm nonramosa, apice fertile phialide singulari aut saepe 2-3 ramis simplicibus fertilibus. Phialides 2-5 verticillatae plerumque ampulliformes 3.2-7.0 x 2.4- 3.8 pm, phialides terminales plerumque subulatae usque ad 12 pm longae. Conidia viridia levia ellipsoidea vel oblonga plerumque 3.0-4.5 X 1.9-2.5 pm.

TYPUS e solo sub Tritico isolatus "Forestburg, Alberta. Canada" S. Visser leg. XI. 1976, DAOM 167 161 (pro cultura exsiccata) .

Colonies growing moderately rapidly, 6.5-8 cm in diameter . - .

after 4 days; mycelium coarse, woolly, white, conspicuous on PDA. Conidiation partly effuse on PDA, on other media typically in numerous, flat or cushion-shaped pustules up to 5 mm in diameter (Fig. 25), often appearing loose and irregular in outline; quickly shading to characteristic yellow-green shades, at first yellowish glaucous or water green, than near pois green (XLI) to tea green or vetiver green, and in age andover green to sage green, artemesia green or slate olive (XLVII), occasionally fringed with a narrow band of white mycelium. Reverse conspicuously pigmented (especially on MA) in yellow shades, citron green (XXXI) to antimony yellow or yellow ocher (XV). Exudate not observed. Odour faintly moldy. Hyphae hyaline to subhyaline, mostly smooth-walled or rarely with irregular fine roughenings, mostly 2-7 p m wide, or submerged hyphae up to 14 pm wide. Chlamydospores few, produced on submerged mycelium or rarely on aerial hyphae in old cultures, intercalary, or terminal on short hyphal branches, mostly ellipsoidal to subglobose and 6-12 x 4-9 p m (Fig. 30), rarely cylindrical and up to 16 x 10 pm; wall hyaline, smooth, up to 1.5 pm thick; contents distinctly granular and greenish. Conidiophores hyaline, smooth-walled, mostly 5-6.5 pm wide, but up to 8 pm wide near the base, highly branched but with branches short giving the conidiophore a linear appearance; primary branches mostly 1- to 3-celled but up to 5 cells long near the base of the conidiophore, arising at nearly right angles and at regular intervals in whorls of 2 or 3; frequently rebranched, with secondary branches short, 1- or 2-celled, arising in whorls of 2 or 3; terminal cells broadly cylindrical, 4.5-12 x 4-6 pm; the upper part of the conidiophore appears stiff and relatively straight, and is nonfertile and unbranched for about 60-120 pm above the fertile part (Figs. 27, 28); the apex is always fertile at maturity and ter-

FIGS. 22-24. Trichoderrna fertile. Conidiophores ( ~ 7 5 0 ) with short, fertile branches at the apex. Conidia ( X 1500). Fig. 22. DAOM 167161. Type isolate, Fig. 23. DAOM 167163. Fig. 24. DAOM 167070.

minated by a single apical phialide, or more often by 2 or 3 simple, short, fertile branches or combinations of branches and lateral phialides; the upper nonfertile part of the conidiophore tapers gradually from 4-6 pm wide just above the fertile part to about 2.5 pm wide below the terminal phialide, and is conspicuously septate (4-34 pm apart) with the septa more closely spaced near the apex. Phialides mostly ampulliform (Fig. 29), 3.2-7.0 x 2.4-3.8 pm, slightly constricted at the base, abruptly constricted apically to a short neck about 1 . 1 pm wide; usually arising in whorls of 2-5, less often singly; terminal phialides usually subulate, up to 12 pm long and about 3 pm wide. Conidia ellipsoidal to oblong (Fig. 3 I), mostly 3.0-4.5 x 1.9-2.5 pm (avg. 3.6 X 2.1 pm), nearly parallel-

sided, both ends broadly rounded or with the base narrowed slightly; smooth-walled, medium green.

MATERIAL EXAMINED: CANADA: ALBERTA: Calgary, soil tanks at University of Calgary, VI. 1977, S. Visser (DAOM 1671 63); Forestburg, wheat field soil, XI. 1976, S.V. (DAOM 167 17 1 TYPE culture, 167 162); Southern Alberta, isolated from Carthamus tinctorius L., VI.1989, R. J . Howard (DAOM 21 1697); QUEBEC: Lacolle, pine forest soil, V11.1975, P. Widden (DAOM 167070); UNITED KINGDOM: Gisburn Forest, moorland, Picea abies plantation, isolated from washed soil particle, A,-horizon, P. Widden LP142, LP143 (DAOM 1951 17, 1951 18).

NOTES: Trichoderrna fertile can be distinguished readily by the bright yellow-green conidiophore pustules and conspicuous

2384 CAN. I. BOT VOL. 69. 1991

BISSETT: I1 2385

deep yellow pigments in the colony reverse on MA and BLA. The morphology and branching of the conidiophore are closest to T. spirale, and these two species are distinguished from T. hnmaturn and similar species by the broader conidiophore main axis (especially toward the apex), and somewhat smaller conidia. Trichoderma fertile is distinguished from T. spirale by characteristics of the apical conidiophore elongation, which is straight and usually bears several short, fertile, apical branches in the former species, and is spiral or coiled and always nonfertile in T . spirale.

Trichoderma glaucum Abbott ( 1926) was described as having conspicuous lime-green conidiation, perhaps similar to that in T. fertile. However, Abbott (1926) described the conidia of T. glaucum as globose to ovoid, with dimenisons 3.5-4.0 x 2.8-3.2 pm, which are considerably broader than conidia of T. fertile.

5. Trichoderma JZavofuscuin (Miller, Giddens & Foster) comb.nov. Figs. 32-37

=Gliocladium flavofuscum Miller, Giddens & Foster, Mycol. 49: 793. 1957

Colonies growing rapidly, 7-9.5 cm in diameter after 4 days; aerial mycelium floccose to woolly, white or greyish. Conidiation abundant, mostly effuse and covering the plate; occasionally forming fascicles, or spreading, flat to cushion- shaped pustules (Fig. 33) concentrated near the margin; very quickly turning yellowish brown shades from chamois, isa- bella (XXX) or tawny olive (XXIX) to deep olive buff (XL) or old gold (XVI). Reverse colourless or slowly developing dull yellowish or drab shades. Exudate colorless to pale amber, in small droplets in the aerial mycelium. Odour indistinct. Hyphae hyaline, smooth-walled, 1-14 pm wide. Chlamydo- spores fairly abundant in older cultures, intercalary or terminal, solitary, subglobose to ellipsoidal or pyriform, 6-15 pm in diameter, subhyaline to pale greenish, smooth-walled, wall up to 1.0 pm thick. Conidiophores from effuse areas of conidiation arising from aerial hyphae, 25-140 pm long x 4-5.5 pm wide, subhyaline, occasionally anastomosing with adjacent conidiophores, the basal part unbranched and nonfertile, or sparingly branched, at the apex with a cluster of 3- 5 adpressed phialides, or a mixture of branches and phialides, branches near the apex arising at acute angles and appressed toward the apex of the conidiophore; conidiophores from pustules more complexly branched, up to 8 pm wide near the base, narrowing to 4-6 pm wide for the most part; subhyaline or pale brownish, at the base branched sparingly and irregularly at nearly right angles; branches short, mostly 1- or 2-celled; toward the apex with branches arising at more acute angles and reflexed toward the apex; final branches mostly 1- celled, cylindrical to slightly swollen, 4-14 x 3.5-5.5 p.m. Phialides ampulliform to lageniform (Fig. 35), mostly 5-10 X 2.6-5.0 p m (or phialides from effuse areas of conidiation subulate, up to 12 pm long, and mostly about 2 pm wide); arising usually in terminal clusters of 2-5, rarely arising laterally on the conidiophore or its branches, often crowded with tips convergent and conidia from adjacent phialides coalescent into large heads; constricted at the base, narrowing to a conid-

ium bearing tube up to 3 pm long and 1-1.5 pm wide, subhyaline to pale yellowish or brownish. Conidia broadly ellipsoidal to subglobose or obovoid (Fig. 36), 3.0-5.3 x 2.4- 4.3 pm (avg. 4.2 x 3.2 pm), both ends broadly rounded or the base slightly narrower, appearing relatively thick-walled, smooth-walled or in age appearing slightly roughened due to an irregular mucilaginous covering, appearing slightly rugose at high magnifications (SEM, Fig. 37), pale brownish.

MATERIAL EXAMINED: UNITED STATES: GEORGIA: Dougherty Co., isolated from soil, 2.VIII. 1956, A. A. Foster 1263 (DAOM 167652 ex ATCC 13308 TYPE culture).

NOTES: Trichorlerma jlavofuscutn is recognizable by the brown conidia produced mostly in flat, spreading conidiogenous pustules. The relatively large conidia and irregularly branched, broad conidiophores ally this species with T. crassum and T. virens. In addition to conidium colour, T. jlavofuscum differs from T. virens in having conidiophores mostly arranged in flat pustules, and from T. crassum in having the conidiophore main axis branched and fertile to the apex.

6. Trickoclerma anamorph of Hypocrea gelatinosa (Tode:Fr.) Fr. (1849), Summa Veg. Scand. p. 383 Figs. 38-47

Colonies growing relatively slowly, 2-5.5 cm in diameter after 5 days; aerial mycelium lacking, or caespitose to matted, white to buff or greyish. Conidiation sparse and effuse, or forming numerous, small, irregular fascicles (Fig. 40) up to 2 mm in diameter (especially on BLA); white at first, slowly turning dull green, from water green (XLI) to vetiver green, pea green or andover green (XLVII), and finally near leaf green to dull blackish green (XLI) in areas of dense conidiation. Reverse colourless to yellow or orange, from amber yellow (XVI), cream-buff or chamois (XXX), to deep colonial buff, olive-ocher (XXX), ochraceous orange (XV) or orange cinnamon (XXIX). Exudate lacking. Odour faint, yeast-like. Hyphae hyaline, usually smooth-walled, occasionally with irregular wall thickenings and appearing rugose (Figs. 44,45), 2-9 pm in diameter. Chlamydospores infrequent, restricted to submerged mycelium, subhyaline to pale greenish, solitary, terminal or intercalary, ellipsoidal to subglobose or obovoid, 4-8 pm in diameter, relatively thin-walled. Conidiophores hyaline to indistinctly yellowish, smooth-walled or with irregular wall thickenings near the base, occasionally with rugose roughenings in age; 3-4 pm wide for the most part, but up to 8 pm wide near the base, sparingly and simply branched; primary branches comparatively uniform in length, usually arising in pairs and at regular intervals, occasionally arising singly or in verticils of three, arising at more or less acute angles and usually curved toward the conidiophore apex; apices of conidiophores and primary branches usually with a Gliocladium-like head consisting of 2-4 branches (1 or 2 cells in length) bearing verticils of 3-5 adpressed phialides, or combinations of phialides and secondary bra<ches (Fig. 42); immature conidiophores may have an elongate sterile apex during the growth phase but are always 'wile at the apex at maturity; cells of the ultimate branchc. are nearly cylindrical and mostly 5- 10 x 2.4-3 pm. Phialides mostly lageniform to ampulliform, 5.5-12.0 x 2.7-3.3 pm, or terminal phialides subulate and

FIGS. 25-31. Trichodermu fertile. Fig. 25. Conidiogenous pustules on BLA after 12 d. x6. Scale bar = I mm. Fig. 26. Young conidiophores showing the development of fertile branches at the apex. x 200. Scale bar = 20 km. Figs. 27 and 28. Mature conidiophores showing nonfertile extension with fertile branches at the apex. x 500. Scale bars = 10 pm. Fig. 29. Ampulliform phialides on widely divergent branches. X 1250. Scale bar = 5 km. Fig. 30. Intercalary chlamydospores. ~ 6 0 0 . Scale bar = 10 km. Fig. 31. Ellipsoid to oblong conidia. x 1250. Scale bar = 5 p,m. Figs. 25 and 27-31. DAOM 167161. Type isolate. Fig. 26. DAOM 167162. Figs. 26-31. Interference contrast.

FIG 32. Trichorlerttin~l~~~~~,fii~cii~~~. Conidiophore ( x 750) and conidia (X 1500). DAOM 167652 ex ATCC 13308. Type isolate.

up to 13 x 2-3 p m (longer in areas of effuse conidiation). Conidia obovoid to broadly ellipsoidal or subglobose (Fig. 46). broadly rounded at both ends, or with the base slightly pointed, mostly 2.5-4.5 (5.5) x 2.0-3.1 p m (avg. 3 .4 x 2.7 p m ) , smooth-walled, greenish; conidia from adjacent phialides often coalescing into large gloeoid masses (Fig. 41).

MATERIAL EXAMINED: CANADA: QUEBEC: h c o l l e , isolated from spruce forest soil, IV. 1975, P. Widden (DAOM 167063); ENGLAND: Cambridge, Wandlebury , ascospore isolate from Hypocrecr gelaritzosa (Tode:Fr. ) Fr. on Accr pseu- doplatarzus L. , 3.XI. 1962 (DAOM 167631 ex CBS 254.62 =

IMI 903 10); NETHERLANDS: Dobersdorfer See, ascospore isolate from H. gel~tirzosa on Fagus silvatica L., W. Gams (DAOM 167639 ex CBS 484.67); UNITED STATES: NORTH CAROLINA: Raleigh, Schenck Forest, isolated from soil, V. 1966, R. M. Danielson (DAOM 145646).

NOTES: The anamorph of Hypoct-ec~ gelatinosa is distinguished by the production of numerous, irregular, dull green conidiogenous fascicles up to 2 mm in diameter (Fig. 40). The irregularly or sparingly branched conidiophores, and relatively large, obovoid conidia indicate a possible relationship with T. virens and similar species. However, in the anamorph of H. gelatinosn, conidiophores usually are unbranched at the base, toward the apex bearing alternate or paired branches, with a Gliocladium-like head of adpressed branches and phialides at the apex.

Observations by Webster (1964) on the morphology of single ascospore isolates of H. gelatinosa were similar to the current observations. Some other species in Hvpocrecl subsection

Ct.rop1r.r have similar ana~norphs. e .g . . H. slrhlr//rcr Doi (Doi 1971). H. Ilrt~o-l>ir-rt~s Doi (Doi 1972). and H. errgilloc.rcr Phil. & Plowr. (Doi 1973).

7 . Trir.llod~rnrtr hattlctrl/tt~ (Bon.) Bain.. Bull Trimest. Soc. Mycol. Fr. 22: 131. 1906 Figs. 18-55

=Vo~/ic~illilrtt~ /lcrttnrri/ttr Bon.. Handb. allg. Mykol. p. 97. 1851

P c ~ c l ~ ~ h ~ r ~ i ~ r t t ~ 11(rttlclr111t1 (Bon . ) Sacc.. Rev. Mycol. 7: 160. I885

=PIl~111ciro/ricl11~11 I ~ e i t t ~ ~ ~ r ~ ~ t t ~ (Bon.) Oud. . Ned. kruidk. archf. 3(2): 908. 1903

Colonies growing moderately rapidly, 3.5-6 c m in diamcter after 3 days: niycelium mostly submerged, the limited aerial myceliuni is floccose. white to greyish. Conidiation is in compact, cushion-shaped or lieniispheric;~l p ~ ~ s t u l e s (Fig. 50) up to 5 nim (rarely 10 mm) in diameter. often distributed concentrically or aggregated near the colony margin; p ~ ~ s t u l e surface appearing velvety due to numerous. flexuous. delicate. sterile conidiophore apices. white at first, becoming greenish glnu- cous (XLI), then bluish green shades fro111 celandine green to near artemesia green, Russian green or dark porcelain green, and finally lily green, slate olive (XLVII), nickel green or dusky green (XXXIII) in age. Reverse colorless. Exudate LISLI- ally lacking, occasionally in small droplets near colony origin, colorless to pale greenish yellow (PDA). Odour indistinct. Hyphae hyaline. smooth-walled, rnostly 1-7 p m in diameter: submerged hyphae up to 12 p m diameter. Chlamydospores sometimes abundant (Fig. 54), terminal or intercalary, solitary, subhyaline. subglobose to broadly ellipsoidal o r pyriform, ~nost ly 5-15 p m in diameter. in the submerged mycelium occasionally up to 3 3 x 18 pni ; wall smooth, usually up to 1 pnl wide, in older cultures up to 2 p m wide. Conidio- phores hyaline, smooth-walled or occasionally with irregular wall thickenings near the base, main axis appearing straight and stiff, 5-10 p m dianieter near the base, tapering to 3.5- 5 p m over most of the length, lower part ofconidiophore main axis regularly branched, primary branches relatively short, usually in whorls of 2-5, occasionally arising singly. often highly rebranched, ultiniate branches niostly I-celled, barrel- shaped or short cylindrical, mostly 3.5-7 x 3-5 pm: upper part of conidiophore main axis sinuous or niore often strongly undulate or hamate (Figs. 51. 52), branching irregularly, sterile for about 100 pni to the apex. or occasionally with a single. terminal phialide in age, apices at maturity narrow, acute. Phialides subglobose to ellipsoidal or ampulliforrn (Fig. 53), 3.3-5.6 X 2.8-3.5 p m , constricted at the base, narrowing abruptly at the apex to a very short conidium bearing tube about 0 . 7 p m wide; mostly arising in crowded whorls of 3- 6 . Conidia oblong to ellipsoidal (Fig. 5 3 , 3.0-4.5 x 2.1- 2 .8 p m (avg. 3 .9 X 2.5 pm) , apex broadly rounded, base narrower or slightly pointed, smooth- and relatively thin- walled, dilute green.

SELECTED MATERIAL EXAMINED: CANADA: BlZl'rlSH COLUMBIA: Burnaby: isolated from agricultural soil, VIII. 1978, M . Leggett (DAOM 177752); isolated from Scler- oti~1172 cepivorut~~ Berk., VI. 1980, M.L. (DAOM 177753); Squamish, log of Popu1lt.s tric.hocarpa Torr . 8: Gray, 21.X. 1982. E. C . Setliff and K. Seifert (DAOM 188956); ONTARIO: Ashton, (/bnus a?nericatlc~ L. bark, 30.IX. 1979, J. Bissett (DAOM 172844); Cochrane, soil, V . 1984, M. T. Dumas (DAOM 199079); Kirkland Lake, rotten wood, 16.V. 198 1, G. P. White (DAOM 180143); Ottawa: Epipactis

BISSETT: II 2387

FIGS. 33-37. Trichodermaflavofuscum. DAOM 167652 ex ATCC 13308. Type isolate. Fig. 33. Conidiogenous pustules on MA after 12 d. X 6. Scale bar = 1 mm. Fig. 34. Conidiophore showing irregular, divergent branching with appressed verticils of phialides. x 500. Scale bar = 10 pm. Fig. 35. Ampulliform phialides. x 1700. Scale bar = 5 pm. Fig. 36. Broadly ellipsoid to obovoid conidia. x 1250. Scale bar = 5 pm. Fig. 37. Conidia with surface inconspicuously roughened (roughenings partly obscured by a sheath-like or mucilaginous covering). X 8500. Scale bar = 1 pm. Figs. 34 and 36. Interference contrast. Figs. 35 and 37. SEM after fixation in osmium tetroxide vapour and air drying.

latifolia (L.) Crantz roots, VII. 1978, W. Illman (DAOM 167776); dead stump, 17 .IV. 1980, J.B. (DAOM 176022); water colour paint set, 11 .I.1980, J.B. (DAOM 174457, 174462); Thuja occidentalis L. rotten stump, 1 .IV. 1980, N. Grainger (DAOM 175923); Lens culinaris L. seedlings, E. P. Schneider (DAOM 183966); Mississauga, Spinacia oler- acea L. roots, 27.1.1976, A. A. Reyes (DAOM 155428); Nepean: Betula papyrifera Marsh. dead stump, 3.1V.1980, N.G. (DAOM 175932); Pinusstrobus L. log, 3.IV. 1980, N.G. (DAOM 175928); Tarzwell, Populus sp., 26.VI. 1981, G.P.W. (DAOM 180478); Vineland Research Station, Prunus sp. mahaleb understocks, 2.VI.1970, W. k. Allen (DAOM 129988; QUEBEC: Lacolle: pine forest soil, V. 1975, P. Widden (DAOM 167067); spruce forest soil, IV,V,VI. 1977, P. W. (DAOM 167053, 16492 1, 164925, 167057 = neotype dried specimen from culture); Gatineau Pk., Tsuga canadensis (L.) Carr. stump, 9.1X.1980, J.B. & N.G. (DAOM 177711b); UNITED STATES: NORTH CAROLINA: Goldsboro, forest nurs- ery soil, VII.1968, R. M. Danielson (DAOM 167416 = ATCC 26798 = WFPL 231A); Raleigh: L- and F-horizons of mixed hardwood forest soil, IV. 1969, R.M. D. (DAOM

165778 = ATCC 28033, DAOM 166120 = ATCC 28034); 0-2 cm soil horizon of loblolly pine stand, V. 1969, R.M.D. (DAOM 165780 = ATCC 28039); OREGON: Marion Co., Pseudotsuga menziesii stumps and roots infested with Phelli- nus weirii, VII-VIII. 1984, B. Goldfarb BG-2 19- 12 (DAOM 195055); Rainier, decayed roots of Pseudotsuga menziesii, E. Nelson (DAOM 195 140); VIRGINIA: Hopewell, IX. 1968, R.M.D. & C. B. Davey (DAOM 145591); no locality data, container media amended with composted hardwood bark, G. Kuter 29, 675 (DAOM 195123, 195121).

NOTES: Type or authentic material of T . harnatum is not available, as Bonorden collections are not known to have sur- vived in herbaria. The original description and illustration by Bonorden (1851) clearly represents T. hamatum or a closely related species. Bainier (1906) provided a detailed illustration of T. hamaturn, however, his observations were not based on authentic material. The name, T . hamatum, should be retained for the often-cited species with hamate, sterile conidiophore apices. Consequently, a neotype, DAOM 167057 (dried specimen from a culture isolated from spruce forest soil, Quebec,

C A N . J . BOT VOL. 69, 1991

FIGS. 38 and 39. Trichorlertnn anarnorph of Hypocren gelntirzosa. Conidiophores ( x 7 5 0 ) and conidia ( X 1500). Fig. 38. D A O M 167639 ex CBS 484.67. Fig. 39. D A O M 167631 ex CBS 254.62 = IMI 90310.

Canada), is selected to represent this common and widely distributed species.

Verticillium cellulosae Daszewska (Daszewska 19 12) and Pachybasium bulbicol~in? Tochinai in Tochinai and Shimada (1 93 1) appear similar to T. harnatum; however, their original descriptions are inadequate for precise identification.

Trichoderma pubescens, T . strigosum and T. harnatum are morphologically similar species producing narrow, ellipsoidal conidia of moderate size (3-4.5 x 2-3 pm) on verticillately branched conidiophores. The three species also all have abundant, mostly subglobose chlamydospores commonly to 12 pm in diameter. They are differentiated primarily by the morphology of the nonfertile conidiophore elongation, which is relatively stout, coiled, and undulate or hamate in T. harnatum, giving the pustules a velvety appearance. Trichoderma fasciculatum and T. strictipilis may also be related to this group, based on the morphology of the conidiophore and branching system, although the latter two species have smaller and more loosely organized conidiogenous pustules or fascicles, and shorter conidia.

8. Trichoderma harzianum Rifai, Mycol. Pap. 116: 38. 1969 Figs. 56-63

= Trichoderma inlzamaturn Veerkamp & W . Gams, Caldasia 13(65): 710. 1983

Colonies growing rapidly, most isolates 7-9 cm in diameter after 3 days; aerial mycelium floccose, white to greyish or rarely yellowish (BLA). Conidiation predominately effuse (PDA), frequently covering the entire surface of the plate on

media with high sugar concentrations, or on MA initially producing compact, flat pustules up to 8 mm in diameter, often concentric or concentrated near the margin of the plate, frequently concrescent into large irregular masses, pustule surface appearing granular or powdery owing to dense conidiation; pustules in glaucous shades at first, rapidly turning dark green from pistachio green to dark American green, dusky yellowish green or dull blackish green (XL), often fringed by sterile white mycelium; areas of effuse conidiation often yellowish green shades (PDA) from near lime green (XXXI) to deep grape green (XLI), vetiver green or andover green (XLVII). Reverse colourless to dull yellowish, ochraceous- buff, pale drab shades, or darker in some isolates (BLA) near ferruginous (XIV); a few isolates producing abundant yellow crystals in agar on MA and BLA. Exudate colourless to amber or greenish-yellow, abundant in some isolates (PDA). Odour indistinct or faintly earthy. Hyphae hyaline, smooth-walled, mostly 2-7 pm in diameter, or submerged mycelium occasionally up to 12 pm in diameter. Chlamydospores fairly abundant, intercalary and terminal on short branches, solitary, contents subhyaline to pale yellowish or brownish in age, subglobose to ellipsoidal or pyriform, mostly 4-12 pm diameter; wall hyaline, up to 1 pm thick. Conidiophores hyaline, smooth-walled, straight or flexuous, up to 8 pm wide near the base, tapering to 2.5-4.5 pm wide for most of their length, macronematous conidiophores highly branched (Fig. 60), primary branches arising nearly at right angles, or bent slightly toward the apex, usually in whorls of 2 or 3, becoming pro-

FIGS. 40-47. Trichoderma anamorph of H. gelatinosa. DAOM 167639 ex CBS 484.67. Fig. 40. Conidiogenous fascicles on BLA after 12d. x 6. Scale bar = 1 mm. Fig. 41. Conidiogenous fascicle showing gloeoid heads of conidia at conidiophore apices, x 170. Scale bar = 50 pm. Fig. 42. Apex of penicillately branched conidiophore. x 600. Scale bar = 10 pm. Fig. 43. Lageniform, convergent phialides. X 1250. Scale bar = 5 pm. Figs. 44 and 45. Irregular wall thickenings on older mycelium. x 1250. Scale bars = 5 pm. Fig. 46. Obovoid to broadly ellipsoidal conidia. X 1250. Scale bar = 5 pm. Fig. 47. Conidia showing smooth walls at high magnifications. X 8500. Scale bar = 1 pm. Figs. 42-46. interference contrast. Figs. 41 and 47. SEM on nonfixed, air-dried material.

gressively longer toward the base, complexly rebranched with secondary branches in whorls of 2-4, entire structure more or less broadly pyramidal; ultimate branches mostly 1-celled, cylindrical or swollen, mostly 3.5-10 x 2.5-6 pm; conidiation develops first on the lowermost branches of the conidiophore while the apex is still growing, during this develop- mental period an infertile apical extension of the conidiophore may extend 150 pm ahead of the lower, branched, fertile part; this apical extension is cylindrical, straight, mostly about 3 pm

diameter with septa 7-30 pm apart and closer together near the apex; at maturity the conidiophore is regularly branched and fertile to the apex. Phialides ampulliform to subglobose or lageniform (Fig. 60), mostly 3.5-7.5 x 2.5-3.8 pm, or terminal phialides up to 10 pm long, markedly constricted at the base, strongly swollen in the middle, and abruptly tapered to a narrow conidium-bearing tube about 0.7 pm wide and up to 1.5 pm long, arising mostly in crowded and divergent whorls of 2-6 on the terminal branches, occasionally arising

CAN. J . BOT V01.. 69. 1091

V

FIGS. 48 and 49. Trichoderrna hamaturn. Conidiophores ( X 750) and conidia ( X 1500). Fig. 48. DAOM 164925. Fig. 49. DAOM 175923.

singly or in whorls laterally on the conidiophore or its branches, rarely conidia may be produced on a short lateral neck from penultimate, intercalary phialides (aphanophial- ides). Conidia subglobose to obovoid or short ellipsoid (Fig. 62), mostly 1.7-3.2 x 1.3-2.5 p m (avg. 2 .4 x 1.9 pm), apex broadly rounded, base more narrowly rounded or slightly pointed, appearing smooth-walled, at high magnifications (SEM) smooth-walled (Fig. 63), or less often very minutely roughened, subhyaline to pale green.

SELECTED MATERIAL EXAMINED: AUSTRALIA: WESTERN

AUSTRALIA: Manjimup, isolated from inner bark of stumps of Euccrlyptus diversicolor infested with Armillaria luteobuba- lina, VI. 1986, N. Malajczuk, E. Nelson & M. Pearce (DAOM 196960). CANADA: ALBERTA: Kananaskis Valley, Mt. Allen: 0-2 cm deep, alpine eutric bmnisol, grass slope, 1900 m elevation, 18.VI. 1969, 4.1X.1971, J. Bissett JB543, JB296 (DAOM 167086, 167088); Calgary: isolated from top- soil, VI. 1977, S. Visser SV1675 (DAOM 167 164); Edmon- ton, rotting Populus sp. log, J. W. Carmichael, 1964 (DAOM 175953 = UAMH 2052); Forestburg, strip coal mine, isolated

from mineral soil, XI. 1976, S . V. SV 101 1 (DAOM 167 166); Lethbridge, Lethbridge Lodge, stem of ornamental Scheflera, 5.IV. 1976, J. Traquair (DAOM 17237 1); Waterton Lakes National Park: Belly River Trail, isolated from Populus sp. log, 9.VIII. 1980, G. P. White GPW8 14b (DAOM 176918b); Rowe Lake trail, isolated from moose dung, 6.VIII. 1980, G.P.W. GPW754c (DAOM 176858~); Westlock, woodchips, 1978, J.W.C. (DAOM 175954 = UAMH 4075); BRITISH COLUMBIA: Cloverdale, isolated from organic muck, pH 4.8, VIII. 1978, M. Leggett (DAOM 177750); Vancouver Island: Cathedral Grove: isolated from P. menziesii log in coniferous forest, 15.IV. 1980, N. D. Grainger (DAOM 176232b); on jelly fungus, 15.IV. 1980, N.D.G. (DAOM 176235b); MANI- TOBA: on mushroom log (Pleurotus ostreatus), VII. 1978, N.D.G. (DAOM 167655); NEW BRUNSWICK: Kouchibouguac National Park, Kullock Creek, on moose dung, 17.IX. 1977, S. A. Redhead 2077 (DAOM 16998 la); ONTARIO: Ashton, on bark of Ulrnus americana L . , 23.IV. 1978, 30.IX. 1979, J. Bissett (DAOM 167268, 172839, 172840, 172841); Guelph, isolated from Fesruca elutior seed, 6.1.1945, J. W. Groves 44-

FIGS. 50-55. Trichoderma hamatum. Fig. 50. Compact, velvety-surfaced conidiogenous pustules on BLA after 12 d. x6. Scale bar = 1 mm. Figs. 51 and 52. Undulate to spiral or hamate, nonfertile conidiophore extensions. x 200. Scale bars = 20 pm. Fig. 53. Ampulliform phialides. x 1250. Scale bar = 5 pm. Fig. 54. Abundant, subglobose chlamydospores in submerged mycelium. X 600. Scale bar = 10 pm. Fig. 55. Ellipsoid conidia. x 1250. Scale bar = 5 pm. Figs. 50 and 52-54. DAOM 167057. Fig. 51. DAOM 129988. Fig. 55. DAOM 143957. Figs. 51-55. Interference contrast.

929B (DAOM 15060); Harrow, isolated from field soil, 1977, W. R. Jawis (DAOM 165 126, 165 127); Hearst, soil, V. 1984, M. T. Dumas (DAOM 199083); Kingston, Queen's Univer- sity, isolated from urea-formaldehyde foam insulation (DAOM 190829, 190830, 19083 1, 190833, 190837); March township: on Acer sp. log, 30.X. 1980, N.D.G. & H. L. Dickson (DAOM 1787 1 1, 1787 14); under Ulmus sp. bark, 30.X. 1980, N.D.G. & H.L.D. (DAOM 178713b); Nepean, Bell's Cor- ners: on Thuja occidetltalis log, 3.IV. 1980, N.D.G. (DAOM 175926, 175927); on Ultnus americana log on ground, 3.IV. 1980, N.D.G. (DAOM 175929); Nepean, Cedarview Road, isolated from pileus of Lerititzellus ursitzus, 2.IV. 198 1, G.P.W. (DAOM 179891); Ottawa: isolated from water colour paint set, I l .I. 1980, J.B. (DAOM 174460, 174461); on Sa1i-r sp. stem, 12.111.1980, J.B. (DAOM 175298); Mer Bleue, on Typha latijolia L. dead stalks, 17.IV. 1980, J.B. (DAOM 176021); Dow's Lake, Typha sp., 16.VI.1981, S.A.R. & K. Spicer (DAOM 180 168); isolated from paper, 1 1 .I. 1976. M. L. Florian (DAOM 155629); Seaforth, isolated from Litzutn

usitatissimurn L. seeds, 1.111.1943, J. W.G. 42-8 19A (DAOM 13569); South March, Forced Road, on Acer sp. log, 15.X.1980, N.D.G. & H.L.D. (DAOM 178048, 178054~1); Sudbury, isolated from soil in white spruce woods, 19.XI. 1976, A. Carter (DAOM 17652 1); Thunder Bay, isolated from wood and urea-formaldehyde foam insulation, 15.IV. 1982, 0 . LaRocque (DAOM 183329); QUEBEC: Cant- ley, on Ulmus sp, 21.IX. 1980, H.L.D. (DAOM 177744); Gatineau Park, Etienne Brule Lookout, on Acer sp. rotten log, 10.X.1980, N.D.G. (DAOM 178038~1); Mulvihill Lake, on Ganoderma tsugae Murr., 9. IX. 1980, J. B. & N.D.G. (DAOM 177690d, 177693~1); on Tsugu cariaderisis (L.) Carr stump, 9.1X. 1980, J.B. & N.D.G. (DAOM 177704); Pink Lake, on Fotnes fotnetltarius on Betulu pupyrijera log, 9.1X. 1980, J.B. & N.D.G. (DAOM 177694); Lacolle, isolated from spruce forest soil, VI. 1977, P. Widden 553, 554 (DAOM 164926, 167056); isolated from maple forest soil, VII. 1975, P. W. LP59 (DAOM 167064); Longueuil, isolated from baby powder, 25.11.198 1, H. Boucher (DAOM 1795 15). COLOMBIA:

CAN. J . BOT. VOL. 69, 1991

FIGS. 56-58. Trichodertna harzianum. Conidiophores (X750) and conidia ( X 1500). Fig. 56. DAOM 167268. Fig. 57. DAOM 167665. Fig. 58. DAOM 172839.

Dept. Meta, near Acacias, isolated from maizefield soil, 18.11.1978, 0 . Range1 (CBS 273.78 ex type T. inhamatum). JAPAN: Imomota Is., Okinawa, isolated from leaves collected in a stream, received from M. T. Dunn (DAOM 195138, 195139). HUNGARY: Szeged, isolated from soil (DAOM 167693 = WFPL 161G). NETHERLANDS: Steiner Wald bei Wattenheim, Rheiauen, isolated from Hypocrea sp. on Popu- 111s sp. wood, 5.X. 1968, W. Gams (DAOM 167640 ex CBS 753.68). SRI LANKA: isolated from soil, received from R. M. Danielson (DAOM 191 108). UNITED KINGDOM: DERBY- SHIRE: Calver, isolated from dead wood (DAOM 167671 =

WFPL 160G); Notts, Clumber Park, isolated from Quercus sp. dead wood, 1961,J. E. Harper (DAOM 167660 = IMI 903 12 = CBS 241.63 = UAMH 2545). UNITED STATES: CALI- FORNIA: Gilroy, isolated from Swiss Chard (Beta vulgaris L. var. cicla L.) seed, 23.IX. 1943, J.W.G. 42-I-959A (DAOM 14971); HAWAII: Oahu, Tudd trail, isolated from leaves on ground under Eucalyptus sp., 16.1.1979, H. M. E. Schalkwyk (DAOM 171424); NORTH CAROLINA: Lake Johnson, L- and F- horizons of mixed hardwood forest, pH 6. I, 130 m elevation, IV. 1969, R. M. Danielson T748 (DAOM 165779 = ATCC 28036); Mt. Mitchell, isolated from soil of yellow poplar stand,

1700 m elevation, V. 1969, R.M.D. TI483 (DAOM 165782 = ATCC 28043); OKLAHOMA: Perkins, isolated from sandy loam soil, K. Conway (DAOM 190839); OREGON: Cascade Mts. near Mill City, isolated from wood of Pseudotsuga menziesii, VIII. 1984, B. Goldfarb (196540); Marion CO., P. menziesii stumps and roots infected by Phellitzus wierii, VII-VIII. 1984, B.G. BG-030-2, BG- 163-9, BG-28 1-9, BG- 38 1-6 (DAOM 195039, 195040, 195041, 195042); Pringle Falls Exp. Forest, near Bend, isolated from soil, 1983, J. Reaves (196545); TEXAS: agricultural soil, G. Kenerley (DAOM 195 13 1); VIRGINIA: Hopewell, isolated from very wet soil of cypress swamp, 0-2 cm deep, pH 4.5, 12 m elevation, IX. 1968, R.M.D. T444 (DAOM 165777 = ATCC 28026). VIRGIN ISLANDS: St.-John, isolated from A,-horizon soil (DAOM 167667 = WFPL 160C).

NOTES: Trichoderma harziatluin is readily identified by the conidium morphology, the small (mostly 2-3 x 1.5-2.5 ~ m ) , subglobose conidia distinguishing this species from all others in Trichoderma. The species has little apparent affinity to other species in section Paclzybasiurn. Conidiophores have a pyramidal, verticillate branching structure, lacking a sterile apical elongation at maturity, although developing conidiophores may

FIGS. 59-63. Trichoderma harzianum. Fig. 59. Portion of conidiophore showing highly divergent branching. DAOM 172795. x 500. Scale bar = 10 pm. Fig. 60. Ampulliform phialides and short, broad branches of macronematous conidiophores on the natural substrate. DAOM 167667. X 1250. Scale bar = 5 pm. Fig. 61. Elongate phialides and narrower conidiophore elements in areas of effuse conidiation in culture. DAOM 14971. X 1250. Scale bar = 5 pm. Fig. 62. Subglobose conidia. DAOM 172796. X 1250. Scale bar = 5 p m Fig. 63. Conidia at high magnification (SEM) showing smooth surface. DAOM 171424. X 15 600. Scale bar = 0.5 pm. Figs. 59-62. Interference contrast. Fig. 63. SEM on material fixed with osmium tetroxide and critical point dried.

have a conspicuous sterile elongation in early stages of growth. Conidiophores are less extensively branched at the base than in species producing compact pustules, do not anastomose extensively, and are loosely aggregated into flat, spreading pustules.

A culture from the type collection of T. inhamatum (CBS 273.78) was studied. This isolate was morphologically indis- tinguishable from other isolates assigned to T. harzianum in the current study. Veerkamp and Gams (1983) described T. inhamatum with densely branched conidiophores bearing inflated phialides and branches, indicating the affinity to other species in section Pachybasium. These attributes are typical of

newly isolated cultures of T. harzianum (e.g., Figs. 56, 60). Veerkamp and Garns (1983) regarded T. inhamatum as a species aggregate, based on observed variation in conidium size and colour of the colony reverse. These variations were also noted in the current study, but did not show sufficient corre- lation with other characters to merit further segregation of taxa.

The anamorphs of Hypocrea cerarnica Ellis & Everh. (Doi 1966) and H. dichromospora Doi (1968) are similar to T. harzianum, differing in having a broader conidiophore main axis, and more elongate phialides and conidia. Domsch et al. (1980) list several other species of Hypocrea with T. harzianum-like anamorphs. The anarnorphs of H. microrufa

CAN. J . ROT. VOL. 6'). 1991

FIG. 64. Trichoderrna longipilis. Conidiophores ( x 750) and conidia ( X 1500). DAOM 177227- l A. Type isolate.

Doi (Doi 1972), H. gelatinoperidia Doi (Doi 1972) and H. subalbocornea Doi (Doi 1973) all have small conidia as in T. harzianum. However, according to the published descriptions, conidia tend to be ellipsoid rather than subglobose in these Hypocrea anamorphs. These three anamorph species also lack chlamydospores and are slow growing in culture. Hypo- crea albofulva Berk. and Br. has more irregularly branched conidiophores and larger conidia with dimensions 2.8-3.5 x 1.8-3.0 pm (Doi 1972). Hypocrea pseudogelatinosa Komatsu and Doi and H. nigricans (Imai) Doi both have larger, ellipsoid conidia, up to 5.0 x 3.2 pm and 5.3 x 3.1 pm, respec- tively (Doi 1972; Samuels et al. 1990).

Trichoderma harzianum was the most commonly occurring Trichoderma species in the current study. Nearly 1000 isolates were examined in culture, and these showed limited variation in conidiophore and conidium morphology. The main source of variation was attributable to the relative production of macronematous or micronematous conidiophores. Conidio- phores and phialides from effuse areas of conidiation, which

predominate in many isolates, are more irregularly branched and narrower, and bear predominantly lageniform or subulate phialides (e.g., Fig. 61). Isolates having only effuse conidiation could be mistaken for species in the T. koningii or T. aureoviride species aggregates (Rifai 1969).

Trichoderma atroviride Karsten (1892) has colonies and subglobose conidia similar to T. harzianum. However, conidia are mostly larger than 3.5 pm in diameter in T. atroviride, the conidiophore main axis is narrower and more flexuous, and branches and phialides are more often solitary or paired rather than verticillate (Bissett 1991). The latter species is referred to section Trichoderrna.

Bainier (1906) published a description of a collection clearly referable to T. harzianum, but which he named T. lignorurn (with corresponding figure mislabelled T. truncorum, a typo- graphical error for T. lignorum). Trichoderma lignorum (Tode) Harz is considered a synonym of T. viride Pers.:Fr. by both Hughes (1958) and Rifai (1969).

FIGS. 65-69. Trichoderma longipilis. Compact, hairy conidiogenous pustules on BLA after 12 d. DAOM 177227-la. Type isolate. X 6. Scale bar = 1 mrn. Fig. 66. Spiral, nonfertile elongations of the conidiophore. X 200. Scale bar = 20 p.m. Fig. 67. Ampullifom phialides. X 1250. Scale bar = 5 pm. Figs. 68-69. Short-cylindrical conidia. X 1250. Scale bars = 5 pm. Figs. 66-69. DAOM 164924. Figs. 66- 68. Interference contrast. Fig. 69. Bright field.

9. Trichoderma longipilis sp. nov. Figs. 64-69 Coloniae 6.5-8 cm diametro post 4 dies (20°C), mycelio

aerio sparso in PDA byssaceo albo vel cinerascente, reverso incolorato. Partes conidiiferae pustulas pulvinatas griseovir- ides plerumque minus quam 2 mm diametro facientes. Hyphae hyalinae leves plerumque 1.5-6 pm latae. Chlamydosporae non vidi. Conidiophora hyalina plerumque levia vel basi aspera, basi usque ad 8 pm lata pro parte majore 3.5-5 pm lata parce ramosa, ramis principalibus brevibus solitariis aut alternantibus aut binatis, ramis secondariis plerumque 2-3 verticillatis, ad apicem flexuosa vel spiralia par usque ad 100 pm nonramosa. Phialides 2-5 verticillatae ampulliformes vel subglobosae plerumque 4.2-6.0 x 3.0-4.5 pm, phialides terminales longiores et plus minusve lageniformes. Conidia cinerascentia levia breviter cylindrica vel ellipsoidea plerumque 3.9-5.7 x 2.0-3.0 pm.

TYPUS ex ligno Ulmi sp. isolatus "Cantley, QuCbec, Canada" H. L. Dickson et N . Grainger leg. 25.IX. 1980, DAOM 177227-la (pro cultura exsiccata).

Colonies growing moderately rapidly, 6.5-8 cm in diameter after 4 days, slower on PDA; aerial mycelium lacking or sparse, on PDA with a limited, cobwebby, white to greyish mycelium. Conidiation typically in compact, cushion-shaped to hemisphaerical pustules (Fig. 65) mostly less than 2 mm in diameter but occasionally up to 5 mm in diameter, usually numerous and scattered, or concentrated near the margin; white at first, slowly turning grey-green, from court grey (XLVII) or mineral grey (XLVII), and finally near slate olive (XLVII) or olive-grey shades in age. Reverse colourless. Exudate lack-

ing. Odour indistinct or faintly acrid. Hyphae hyaline, smooth- walled, mostly 1.5-6 pm wide, or submerged mycelium up to 10 p m wide. Chlamydospores not observed. Conidiophores hyaline, usually smooth-walled, but occasionally appearing roughened or with conspicuous wall thickenings toward the base of the conidiophore; up to 8 pm wide at the base, gradually tapering to 3.5-5 pm wide throughout the fertile part of the conidiophore; sparingly branched, all branches arising at nearly right angles; primary branches relatively short, arising singly, alternately, or in pairs, rather sparingly rebranched; secondary branches usually in whorls of 2 or 3; ultimate branches mostly 1- to 2-celled with cells nearly cylindrical or only slightly swollen, mostly 4-8 x 3-4 pm; upper part of conidiophore main axis with a very long, nonfertile part, which is often highly ramified and anastomosing to within 100 p m of the apex; the apical part is unbranched, flexuous to strongly undulate (Fig. 66), and evenly septate (10-24 pm distant); over the unbranched apical part tapering from 4-5 pm in diameter to less than 1 pm wide at the acute apex. Phialides ampulliform to nearly subglobose (Fig. 67), mostly 4.2-6.0 x 3.0-4.5 pm, usually strongly swollen near the middle and more or less constricted at the base, abruptly constricted to a short neck about 0.7 pm wide that is often bent toward the conidiophore apex; arising in whorls of 2-5, (usually in uncrowded whorls of 3), rarely solitary; terminal phialides and phialides from effuse areas of conidiation longer and more or less lageniform. Conidia short cylindrical to more or less oblong (Figs. 68, 69), sometimes constricted slightly at the middle, mostly 3.9-5.7 X 2.0-3.0 p m (avg. 4.8 X 2.4 pm),

CAN. J . BOT. VOL. 69. 1991

FIGS. 70 and 7 1. Trichodermn tninutisporum. Conidiophores ( x 750) and conidia ( x 1500). Fig. 70. DAOM 167069. Type isolate. Fig. 71. DAOM 17593 1 .

in effuse areas of conidiation up to 7.5 x 3.5 pm; both ends broadly or bluntly rounded; appearing smooth- and thin-walled, pale greyish.

MATERIAL EXAMINED: CANADA: BRITISH COLUMBIA: Van- couver Is., Goldstream Prov. Pk., Populus sp. log, 25.IV. 1980, N. Grainger (DAOM 1762396); QUEBEC: Can- tley, Ulmus sp. log, 21.1X.1980, H. L. Dickson & N.G. (DAOM 177227-la, type culture); Lacolle: Maple forest soil, IV.1976, P. Widden (DAOM 167071); Norway Spruce plantation soil, V. 1977, P. W. (DAOM 164924).

NOTES: Trichoderrna longipilis is morphologically similar to T. oblongisporum, both species producing large (average length about 4.5 pm), more or less oblong conidia, with a length to width ratio > 2.0. These two species produce conidiophores and compact, hemisphaerical, conidiogenous pustules resembling those of T. hamatum and similar species. However, conidia are pale green or greyish, and chlamydospores are absent or infrequent and smaller in T. longipilis and T. oblongisporum. Trichoderma longipilis is distinguished from T. oblongisporum primarily by the apical conidiophore elongation, which is strongly undulate and frequently branched in T. longipilis. Viewed microscopically, conidia are greyish in T. longipilis and pale-greenish in T. oblongisporum.

10. Trichoderrna minutisporum sp. nov. Figs. 70-79 Coloniae celeriter crescentes 7-8 cm diametro post 4 dies

(20°C), mycelio aerio sparso in PDA floccoso cinerascente, reverso incolorato vel flavido. Partes conidiiferae pustulas pulvinatas farinosas flavovirides plerumque usque ad 5 mm diametro facientes. Hyphae hyalinae leves plerumque 1-8 pm latae. Chlamydosporae paucae leves subhyalinae subglobosae vel ellipsoideae vel pyriformes plerumque 5-8 pm diametro. Conidiophora hyalina levia vel raro basi irregulatim incrassata, pro parte majore 3-4 pm lata abunde ramosa, ramis principalibus 2-4 verticillatis ad basim conidiophorae elongatis, ramis secondariis verticillatis multis, ad apicem recta vel parum flexuosa ubique ramosa et fertilia. Phialides 3-6 verticillatae plerumque ellipsoideae 2.8-4.3 x 2.7-3.1 pm. Conidia dilute viridia levia late ellipsoidea plerumque 2.5-3.3 x 1.8- 2.3 pm.

TYPUS e solo sylvae isolatus "Lacolle, QuCbec, Canada" P. Widden leg. IV. 1975, DAOM 167069 (pro cultura exsiccata).

Colonies growing rapidly, 7-8 cm in diameter after 4 days; mycelium mostly submerged, on PDA with limited, floccose, greyish aerial mycelium. Conidiation typically in compact, cushion-shaped pustules (Figs. 72, 73), irregularly distributed or concentrated near the margin, and usually up to 5 mm in

FIGS. 72-79. Trichoderma minutisporum. Figs. 72 and 73. Compact conidiogenous pustules with conidia in minute gloeoid balls giving surface a granular texture. Fig. 72. x 3. Scale bar = 2 mm. Fig. 73. x 85. Scale bar = 100 pm. Fig. 74. Apices of immature conidiophores branched and fertile to the apex. x200. Scale bar = 20 pm. Fig. 75. Conidiophore branch showing crowded phialides on highly divaricate branches. x500. Scale bar = 10 pm. Fig. 76. Small, ampullifom phialides on very short branches. x 1250. Scale bar = 5 pm. Fig. 77. Small, ellipsoid conidia. X 1250. Scale bar = 5 pm. Figs. 78 and 79. Ellipsoid conidia showing the smooth surface at high magnifications (SEM). Fig. 78. x 8500. Scale bar = 1 pm. Fig. 79. x 20 000. Scale bar = 0.5 pm. Figs. 72, 74, and 75. DAOM 175931. Figs. 73 and 76-78. DAOM 167069. TYPE isolate. Fig. 79. DAOM 172797. Figs. 73, 78 and 79. SEM, osmium tetroxide vapour fixed, air-dried material. Figs. 74-77. Interference contrast.

VOL. 69. 1991

FIG. 80. Trichoderma oblongispor~m. Conidiophore ( x 750) and conidia ( X 1500). DAOM 167085.

diameter, on malt agar frequently with only few large pustules up to 22 mm in diameter; appearing granular or mealy owing to abundant conidiation, white at first, quickly turning bright green, at first greenish glaucous to corydalis green (XLI), then dark yellowish green (XVIII) to empire green (XXXII) or American green (XLI), and finally elm green (XVII), yew green (XXXI), dark dull yellow green (XXXII) or dusky yel- Iowish green (XLI); yellow hues more pronounced on Czapek's and PDA. Reverse colourless, or on PDA yellowish to drab or pale vinaceous in patches. Exudate lacking. Odour indistinct. Hyphae hyaline, smooth-walled, mostly 1-8 pm wide, or submerged mycelium up to 12 pm wide. Chlamydospores few, subhyaline, subglobose to ellipsoidal or pyriform, mostly 5-8 km in diameter, wall smooth and up to 0.6 km thick. Conidiophores hyaline, smooth-walled, or rarely with irregular wall thickenings basally, mostly 3-4 km wide, slightly wider at the base and at branch points, highly branched; primary branches short near the apex and increasing in length toward the base of the conidiophore, arising at regular intervals in

whorls of 2-4; rebranched regularly to form a highly ramified, pyramidal structure; ultimate branches are mostly I-celled, more or less swollen, 3-4.5 X 3-4 pm; the upper part of the conidiophore is straight or slightly flexuous, fertile, and regularly branched to the apex (Figs. 70, 71), occasionally anastomosing with adjacent conidiophores. Phialides more or less ellipsoidal (Fig. 76), 2.8-4.3(5.0) x 2.7-3.1(4.4) pm, constricted at the base, narrowing to a short but conspicuous conidium-bearing tube about 0.7 pm wide; mostly arising in crowded whorls of 3-6. Conidia broadly ellipsoidal (Fig. 77), both ends broadly rounded or with the base slightly narrower, mostly 2.5-3.3 x 1.8-2.3 pni (avg. 2.8 x 2.0 pm); smooth- and thin-walled (Figs. 78, 79), pale green.

MATERIAL EXAMINED: CANADA: ALBERTA: Kananaskis, isolated from soil FH-horizon under Pitzus cotztorta var. Inri- folia Engelm., 1990, M.A. McLean (DAOM 212372); ONTARIO: Bells Corners. Betiila papyrifera Marsh. wood, 3.IV. 1980, N. Grainger (DAOM 17593 1); Kirkland Lake, Picea mariatza (Mill.) BSP. root, 9.IX. 1982, R. Summerbell (DAOM 191102); Nepean: Betula sp. rotting branch, 5.IV. 1981, G. P. White (DAOM 179741); wood, 2.IV. 1981, G.P.W. (DAOM 179894); Ottawa: interface of urea-formaldehyde foam insulation and wood in wall of residence, 8.VIII. 1979, C. J. Shirtliffe (DAOM 172797); aerial contam- inant in residence, 24.VI. 1982, G.P. W. (DAOM 183975); Pembroke: Retula sp. branch, 19.IV. 198 1, G.P.W. (DAOM 180142); rotting branch, 19.1V.1981, G.P.W. (DAOM 180140); South March: hardwood log, 15.X. 1980, N.G. & H.L. Dickson (DAOM 178046); Acer sp. wood, 15 .X. 1980, N.G. & H.L.D. (DAOM 178050); QUEBEC: Lacolle, hardwood forest soil, IV. 1975. P. Widden (DAOM 167069, type culture); Gatineau Park, Betula sp. wood, 9.IX. 1980, J . Bissett & N.G. (DAOM 177713).

NOTES: Trichoderrna tnitzurisporum is readily distinguished by the bright-green, spreading conidiogenous pustules, and by the small, broadly ellipsoidal conidia. Trichoderma tornento- sum has similar conidiophores and conidia, but the conidiophore of that species has a distinctive coiled or circinate sterile apical elongation. Owing to the dense conidiation, conidiogenous pustules in T. minutisporutn are bright green with the surface appearing mealy, whereas in T . totnetztosutn pustules are bluish green and appear hairy owing to the numerous sterile conidiophore elongations.

1 1. Trichoderma oblongisporum sp.nov. Figs. 80-85 Coloniae 6.5-7.5 cm diametro post 4 dies (20"C), mycelio

in PDA floccoso albo, reverso incolorato vel pallide flavido. Partes conidiiferae effusae aut pustulas applanatas villosas gri- seovirides usque ad 4 mm diametro facientes. Hyphae hyalinae leves plerumque 2-6 pm lata. Chlamydosporae paucae solitariae terminales subhyalinae subglobosae vel late ellipsoideae usque ad 8 pm diametro. Conidiophora hyalina levia basi usque ad 9 pm lata pro parte majore 4-6 pm lata parce ramosa, ramis principalibus solitariis aut alternantibus aut binatis, ramis secondariis sparsis, ad apicem recta aut flexuosa per usque ad 200 pm nonramosa et infertilia. Phialides plerumque 2-3 verticillatae plus minusve ampulliformes 3.3-6.6 X 2.9-3.6 km. Conidia hyalina vel dilute virella levia ellipsoidea vel breviter cylindrica 3.5-5.0 x 1.7-2.8 km.

TYPUS ex ligno Thujae plicatae isolatus "Pacific Rim National Park, British Columbia, Canada" N. Grainger leg. 19.IV. 1980, DAOM 176226 (pro cultura exsiccata).

FIGS. 81-85. Trichoderma oblongisporum. DAOM 176226. Type isolate. Fig. 81. Compact, hairy, conidiogenous pustule, on MA after 30 d. X 6. Scale bar = I mm. Fig. 82. Long, straight, sterile, conidiophore extensions. x 200. Scale bar = 50 pm. Fig. 83. Crowded, ampulliform phialides. x 1500. Scale bar = 5 pm. Figs. 84 and 85. Oblong conidia. Fig. 84. x 1500. Scale bar = 5 pm. Fig. 85. x 1250. Scale bar = 5 pm. Figs. 82-84. interference contrast. Fig. 85. Bright field.

Colonies growing moderately rapidly, 6.5-7.5 cm in diameter after 4 days; aerial mycelium on PDA floccose, white. Conidiation effuse, or forming compact pustules that are irregular in size and shape (Fig. 81), usually up to 4 mm in diameter, and sometimes concrescent into larger masses, appearing hairy due to numerous, usually unbranched, sterile conidiophore apices; at first yellowish glaucous, slowly turning tea green to sage green or artemesia green (XLVII), finally slate olive (XLVII) to olive grey or dark olive (LI) in age. Reverse colorless to pale yellowish (on BLA). Exudate lacking. Odour faintly yeasty. Hyphae hyaline, smooth-walled, mostly 2- 6 pm wide, submerged mycelium up to 1 1 pm wide. Chla- mydospores few, occurring in the submerged mycelium, terminal, solitary, subhyaline, subglobose to broadly ellipsoidal, up to 8 pm in diameter. Conidiophores hyaline, smooth- walled, up to 9 pm wide near the base, gradually tapering to 4-6 pm wide for most of their length; relatively sparingly branched, branches arising at right angles; primary branches arising singly, alternately, or in pairs, sparingly rebranched; ultimate branches 1 - to 4-celled, terminal cells cylindrical to

only slightly swollen, 3.5-6 X 2.8-4.4 pm; upper part of conidiophore main axis with a very long, staight or flexuous, nonfertile part (Fig. 82), often branching once or twice just above the fertile part of the conidiophore, then unbranched for up to 200 pm to the apex; gradually attenuate above the fertile part from about 3 pm to about 1.6 pm wide near the bluntly rounded apex; septa distant (15-40 pm apart). Phialides more or less ampulliform (Fig. 83), 3.3-6.6 X 2.9-3.6 pm, slightly constricted at the base, narrowed abruptly at the apex into a short conidium bearing tube about 0.6 pm wide; uncrowded, usually arising in whorls of 2 or 3, occasionally solitary or in whorls of 4; phialides from effuse areas of conidiation longer and narrower, or subulate. Conidia ellipsoidal to oblong or short cylindrical (Figs. 84, 85), both ends broadly rounded or with the base slightly narrower, 3.5-5.0 X 1.7- 2.8 pm (avg. 4.5 X 2.3 pm), smooth- and thin-walled, subhyaline to pale greenish.

MATERIAL EXAMINED: CANADA: ALBERTA: Heart Mt., near Canmore, isolated from soil at 15- 18 cm depth in Dryas meadow at 1800 m elevation, 7.VI. 1968, J. Bissett (DAOM

CAN. J . BOT VOL. 69. 1991

FIGS. 86-89. Trichoderrnapolysporiim. Conidiophores ( x 750) and conidia ( X 1500). Figs. 86-88. North American isolates with tuberculate conidiophore apices. Fig. 86. DAOM 166990. Fig. 87. DAOM 167082. Fig. 88. DAOM 167156. Fig. 89. European strain with smooth, apical conidiophore extensions. DAOM 16768 1.

167085); BRITISH COLUMBIA: Vancouver Is., Cathedral Grove, Pseudotsuga menziesii log, 15.IV. 1980, N. D. Grainger (DAOM 176232~); Pacific Rim National Park, Thuja plicata Donn. wood, 19.1V.1980, N.D.G. (DAOM 176226 TYPE culture).

NOTES: Trichoderma oblongisporum is allied to T. longipilis, both species having compact, greyish, conidiogenous pustules; similar conidiophore branching systems; and relatively large, oblong to short-cylindrical conidia. Trichodermn oblongisporum is distinguished from T. longipilis in having relatively-straight, usually unbranched, apical conidiophore elongations.

12. Trichoderma piluliferum Webster & Rifai in Rifai, Mycol. Pap. 116: 16. 1969

TELEOMORPH: Hypocrea pilulifera Webster & Rifai, Trans. Br. Mycol. Soc. 51: 511. 1968

Colonies growing slowly, 2-4 cm in diameter after 4 days; mycelium mostly submerged, limited aerial mycelium (PDA) caespitose to matted, white. Conidiation mostly in compact tufts, white. Reverse colourless to dull yellow. Odour indistinct. Hyphae hyaline, smooth-walled, 2-20 pm wide; or submerged mycelium up to 13 pm wide. Chlamydospores infrequent, occurring in the submerged mycelium, intercalary or terminal, solitary, hyaline, subglobose to ellipsoidal, up to

BISSETT: 11 240 1

FIGS. 90-97. Trichoderma polysporum. Fig. 90. Spiral, nonfertile, apical elongations of the conidiophore. DAOM 165070. x 200. Scale bar = 20 pm. Figs. 91 and 92. Tuberculate roughenings on the apical conidiophore extensions. Fig. 91. DAOM 167267. x 500. Scale bar = 10 pm. Fig. 92. DAOM 180150. x 1620. Scale bar = 5 pm. Figs. 93 and 94. Longitudinal sections through tubercles on apical conidiophore extensions. The tubercles contain a homogeneous or aggregated electron-dense material enclosed in a membrane that appears continuous with the outer membrane of the wall of the conidiophore. DAOM 180150. X 48 000. Scale bars = 0.2 pm. Fig. 95. Small, ampulliform phialides on short, swollen branches. DAOM 165070. x 1250. Scale bar = 3 pm. Fig. 96. Small ellipsoidal conidia. DAOM 165070 X 1250. Scale bar = 5 pm. Fig. 97. Conidia showing the smooth surface at high magnifications. Conidia are persistently aggregated in balls in aqueous or phenolic mounts, although the sheath or gelatinous matrix surrounding the conidia is no more evident than in most other species. DAOM 180150. x 7000. Scale bar = 1 pm. Figs. 90, 91, 95 and 96. Interference contrast. Figs. 92 and 97. SEM on osmium tetroxide vapour-fixed, air-dried material. Figs. 93 and 94. TEM on gluteraldehyde and osmium tetroxide fixed material sectioned in Spurr's embedding medium.

12 p,m in diameter. Conidiophores hyaline, smooth-walled, 4- 7 p,m wide, highly branched, branches usually 2- or 3-verticillate, arising at regular intervals, increasing in length toward the base of the conidiophore; upper part of conidiophore main axis straight to flexuous, regularly branched and fertile to the apex. Phialides usually arising in whorls of 2-5 at the apex of conidiophore branches, mostly ampulliform to nearly pyriform, 4.5-6.5 X 2.8-3.5 p,m, or terminal phialides up to 10 p,m long, constricted at the base, abruptly attenuate to a narrow apex, often curved toward the apex of the conidiophore. Conidia globose to subglobose, 2.5-3.5 p,m in diameter, base with a truncate apiculum, smooth-walled, colourless.

MATERIALS EXAMINED: UNITED KINGDOM: DERBYSHIRE: Glossup, Snake Pass, single ascospore isolation from dead culms of Juncus effusus L., J. Webster (DAOM 167683 = WFPL 261A = SHD-M3 182); YORKSHIRE: Dunsop Bridge

near Cuthroe, single ascospore isolation from dead wood of Betula sp., 23.IX. 1962, J.W. (DAOM 167684 = WFPL 261B = SHD-M2638, type isolate).

NOTES: TWO cultures originally isolated from ascospores of Hypocrea pilulifera were examined. Both isolates, however, failed to produce conidiogenous structures. The above description is largely from the descriptions in Webster and Rifai (1968) and Rifai (1969).

The species is distinguished by the subglobose, colourless conidia borne on verticillately branched conidiophores aggregated in compact, white fascicles. Trichoderma polysporum also has colourless conidia, but differs in producing ellipsoidal conidia, and conspicuous, spiral, nonfertile, apical conidiophore elongations. Trichoderma piluliferum may be more closely allied to the Trichoderma anamorph of Hypocrea pla- centula Grove, which was described by Spooner and Williams

CAN. J . BOT. VOL. 69. 109 1

FIG. 98. Triclzorlertnn p~r1~esce11.s. Conidiophore (x7.50) and conidia ( X 1.500). DAOM 166162. Typc isolate

(1990). The latter anamorph species differs in having longer. lageniform phialides 6-10 x 2.5-3 pm, and broadly ellipsoid conidia 2.5-3 x 2-2.5 pm (Spooner and Williams 1990).

13. Trichodermrt polyspor~rltl (Link: Fr.) Rifai, Mycol. Pap. 116: 18. 1969 Figs. 86-97

=Sporotrichum polyspow~n Link, Mag. Ges. Naturf. Freunde, Berl., 7: 34. 1815; Fries, Syst. Mycol. 3: 424. 1832

Colonies growing moderately rapidly, 5-8 cm in diameter after 5 days; mycelium mostly submerged, aerial mycelium limited, caespitose to matted, white. Conidiation developing slowly (usually 7-14 days), mostly in compact, cushion- shaped pustules up to 10 mm in diameter, often concrescent forming large, irregular masses (PDA); pustule surface appearing more or less velvety owing to numerous, flexuous, sterile conidiophore apices; white to cream coloured; in age remaining near white, or turning cream-buff (XXX) to olive-buff (XL) or pale olive gray (LI) in patches. Reverse colourless to dull yellowish. Exudate colourless, in small droplets in the aerial

mycelium. Odour indistinct or slightly mouldy. Hyphae hyaline, smooth-walled, 2- 10 pm; or submerged lnyceliuln up to 15 pm wide. Chlamydospores few. occurring mostly in the submerged mycelium, intercalary or terminal, solitary, hyaline or with subhyaline contents. subglobose to ellipsoidal, 4- 10 pm diameter (mostly about 6 pni in diameter), wall up to 1 pm thick. Conidiophores hyaline, smooth-walled except near the apex, thicker walled and up to 7 ptn wide near the base, tapering to 3-4.5 p,m wide for most of the length. highly branched, branches arising at right angles, primary branches mostly short, usually in pairs, occasionally in verticils of three, secondary branches in whorls of 2-4 (usually 3), ultimate branches mostly 1-celled, short cylindrical or inflated, mostly 3.5-9 x 3-6 p,m; upper part of conidiophore main axis persistently sterile, in most isolates branching once or more just above the fertile part, broad, coarse, spiral-shaped (Fig. 90), tapering from 3-4 p,m wide above the fertile part, to about 1- 1.5 p,m wide at the bluntly rounded apex; conspicuously tuberculate in most isolates (Figs. 91, 92), especially toward the apex; conspicuously septate with septa 8-34 p,m distant; occa-

FIGS. 99-106. Trichoderma pubescens. DAOM 166162. Type isolate. Fig. 99. Compact, hemispherical conidiogenous pustules with downy surface texture. x 6. Scale bar = 1 mm. Fig. 100. Branched conidiophore extension with narrow, acuminate apices. x 500. Scale bar = 10 pm. Figs. 101 and 102. Highly ramified conidiophores with crowded verticils of phialides. Scale bars = 10 pm. Fig. 101. X 500. Fig. 102. X 600. Fig. 103. Ampulliform phialides on short, swollen branches. x 1250. Scale bar = 5 pm. Fig. 104. Large, subglobose chlamydospores in the aerial mycelium in an old culture. x 600. Scale bar = 10 p m Fig. 105. Ellipsoid conidia. x 1250. Scale bar = 5 pm. Fig. 106. Conidia showing smooth surface at high magnifications. x8200. Scale bar = I pm. Figs. 100 and 101. Phase contrast. Figs. 102-105. Interference contrast. Fig. 106. SEM on material dehydrated in ethanol series and critical point dried.

sional isolates with the conidiophore apex smooth-walled and with a solitary, terminal phialide, or a few simple branches terminated by phialides or whorls of phialides. Phialides usually arising in whorls of 2-5 at the apex of the terminal branches, less often laterally on the conidiophore and its branches, occasionally in crowded clusters of up to 7 on inflated terminal cells, mostly ampulliform (Fig. 95), 3.5-7 X 2.7-3.6 pm, constricted at the base, attenuate to a narrow

apex about 0.7 pm wide. Conidia ellipsoidal (Fig. 96), mostly 2.3-3.6 X 1.4-2.2 pm (avg. 3.0 x 1.7 pm), both ends broadly rounded, smooth-walled (Fig. 97), colourless, aggregated in a persistent mucilage or sheath.

SELECTED MATERIAL EXAMINED: CANADA: ALBERTA: Gal- gary, isolated from peat, VI. 1977, S. Visser SV1876, SV 1983 (DAOM 167 156, 167 157); Forestburg, isolated from soil, XI. 1976, S.V. SV1117 (DAOM 16'1 155); Kananaskis Valley,

CAN. J . BOT VOL. 69. 1991

FIG. 107. Trichoderma anamorph of Hypocrea semiorbis. Conidiophore (X750) and conidia ( x 1500). DAOM 167636.

Mt. Allen; isolated from A-horizon of alpine eutric brunisol on grass slope at 1900 m elevation, X. 1968, 18.VI. 1969, J. Bissett (167087); isolated from A- and C-horizons, alpine lithic regosol under Dryas sp. at 2532 m elevation, 9.VII. 1969, J.B. (DAOM 167082); BRITISH COLUMBIA: Gla- cier National Park, Beaver River valley, isolated from moose dung, 19.IX. 1980, S. A. Redhead (DAOM 180150); Lion's Bay, isolated from Pseudotsuga menziesii root rot, 13 .I. 1978, P. W. Penin (DAOM 170599); Vancouver Is., Pacific Rim National Park, isolated from Thuja plicata stump, 2 1 .IV. 1980, N. D. Grainger (DAOM 176227b); isolated from conifer log on ground, 10.IV. 1980, N.D.G. (DAOM 176328); Victoria, isolated from soil, K. Egger I242 (DAOM 185628); NEW- FOUNDLAND: Comer Brook, isolated from slime from pulp and paper mill, VI.1956, D. Brewer 54E (DAOM 63862); ONTARIO: Ashton, isolated from Ulmus americana periderm, 23.IV. 1978, J. B. (DAOM 167267); Hearst, soil, V. 1984, M. T. Dumas (DAOM 199081); Petawawa, isolated from Picea glauca, 19.IX. 1958, K. Shields (DAOM 64046); QUE- BEC: Cantley, underside of fallen conifer log, 21.1X.1980, H. L. Dickson (DAOM 177749~); Gatineau Park, deciduous leaf litter, 10.X. 1980, N.D.G. (DAOM 178042); Lacolle,

spruce forest soil, IV.1975, IV.1976, VI.1977, VII.1977, VIII. 1977, P. Widden (DAOM 167065, 167066, 165070, 166690, 167058); SASKATCHEWAN: Tugaske, isolated from soil, 5.11.1968, M. I. Timonin (DAOM 118918); isolated from Picea mariana yellow spongy decay of root, 3.1.1958, R. D. Whitney S225 (DAOM 57905). UNITED KINGDOM: DER- BYSHIRE: Chatsworth Park, isolated from pine bark, C. Dennis TP9 (DAOM 167679 = WFPL 260A); Gisbum Forest, moorland, Picea abies plantation, isolated from washed soil particle, A,-horizon, P. Widden LP138 (DAOM 1951 16). GER- MANY: KITZBURG: isolated from wheat field soil, 19.111.1963, W. Gams (DAOM 167681 = WFPL 260C). UNITED STATES: NORTH CAROLINA: Raleigh, Schenck Forest: V. 1966, R. M. Danielson T-9 (DAOM 145746); isolated from forest soil under loblolly pine, pH 4.0, 130 m elevation, 1967, R.M.D. T262 (DAOM 165775 = ATCC 28024); WASHING- TON: Bellingham, isolated from soil under red alder, pH 4.6, 40 m elevation, VIII.1969, R.M.D. T1624 (DAOM 166143 = ATCC 28044); Centralia, Lincoln Creek, isolated from forest soil under old growth of Douglas-fir, 0-7 cm depth, pH 6.0, VIII.1968, R.M.D. T555 (DAOM 166138 = ATCC 28029).

FIGS. 108-1 11. Trichoderma anamorph of H . sernior-bis. DAOM 167636. Fig. 108. Small, compact conidiogenous pustules, from culture on MA after 40 d. x 6. Scale bar = 1 rnm. Fig. 109. Long, straight, nonfertile elongations of the conidiophore. x 200. Scale bar = 10 pm. Fig. 1 10. Conidiophore main axis, with short branches frequently in pairs. X 500. Scale bar = 10 pm. Fig. 1 1 1. Ellipsoid to short-cylindrical conidia. X 1500. Scale bar = 5 pm. Figs. 109-1 11. Interference contrast.

NOTES: Hughes (1958) and Rifai (1969) list synonyms for T. polysporum. Trichoderma polysporum can be distinguished readily by the white conidiogenous pustules and conspicuous, spiral, sterile conidiophore elongations. Usually the conidiophore is conspicuously tuberculate near the apex, although a few isolates have smooth conidiophores. Trichoderma piluliferum also has colourless conidia, but conidia in the latter species are subglobose and the conidiophore lacks a sterile apical elongation. Trichoderma croceum has a similar conidiophore branching pattern and a tuberculate, nonfertile conidiophore apex. However, that species develops yellow-green or rosy buff conidial pigments, and conidia are somewhat broader than in T. polysporum.

The tuberculate roughening in T. polysporum and T. croceum are persistent in liquid mounts. In transmission electron microscope observations, the tubercules are enclosed by the outer membrane of the conidiophore wall and filled with a dense, homogeneous, electron-dense material (Figs. 93, 94).

A white-spored fungus resembling T. polysporum has been reported as the anamorph of Hypocrea pachybasioides (Doi 1972; Komatsu 1976). However, the anamorph of H. pachybasioides has young conidia roughened, and conidial masses becoming brown in age (Doi 1972). The conidia of T. polysporum are consistently smooth, even at high magnifications (Figs. 96, 97). Webster and Rifai (1968) described the anamorph of an unidentified Hypocrea species as resembling T. polysporum.

14. Trichoderma pubescens sp.nov. Figs. 98-106 Coloniae 5-8 cm diametro post 4 dies (20°C), mycelio aerio

sparso in PDA floccoso albo, reverso incolorato vel pallide flavido. Partes conidiiferae pustulas hemisphaericas pubes- centes flavovirentes usque ad 6 mm diametro facientes. Hyphae hyalinae leves plerumque 1.5-10 1J.m latae. Chla- mydosporae denique abundantes solitariae terminales vel intercalares leves subhyalinae vel viridulae plus minusve subglo-

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FIG. 1 12. Tricho~ferma spirale. Conidiophore ( x 750) and conidia ( X 1400). DAOM 171919.

bosae 8-34 pm diametro. Conidiophora hyalina levia basi usque ad 8 p m lata pro parte majore 3.5-5 pm lata abunde ramosa, ramis principalibus confertis 3-5 verticillatis comparate brevibus, ramis secondariis 2-3 verticillatis, ad apicem flexuosa vel laxe spiralia gracilia nonramosa et sterilia. Phial- ides 2-4 verticillatae ampulliformes vel lageniformes plerumque 4.0-6.0 x 2.2-3.5 pm, phialides terminales usque ad 8 p m long. Conidia dilute viridia levia ellipsoidea 3.1-4.7 x 2.0-2.9 pm.

TYPUS e solo sylvae isolatus "Raleigh, North Carolina, United States" R. Danielson leg. IV. 1969, DAOM 166162 (pro cultura exsiccata).

Colonies growing moderately, 5-8 cm in diameter after 4 days; aerial mycelium limited, floccose, white (PDA). Con- idiation typically in numerous, compact, hemisphaerical pustules (Fig. 99) up to 6 mm in diameter (mostly less than 2 mm in diameter), occasionally arranged concentrically, surface appearing downy due to numerous, thin, branched sterile con-

idioiphore apices; white at first, gradually turning bright green shades from glaucous (XLI), then deep dull yellow green (XXXII) to American green (XLI), and finally dark dull yellow green (XXXII) to dusky yellowish green (XLI). Reverse uncolored or pale yellowish (MA). Exudate not observed. Odour indistinct. Hyphae hyaline, smooth-walled, mostly 1.5- 10 pm in diameter, or submerged mycelium up to 12 prn in diameter. Chlamydospores abundant in old cultures (Fig. 104), especially in the submerged mycelium, terminal or intercalary, solitary, more or less subglobose, 8-34 pm in diameter (mostly more than 20 pm in diameter), wall smooth, subhyaline, up to 2 pm thick; contents hyaline to pale greenish, large chlamydospores often collapsing. Conidiophores hyaline, smooth-walled, coarse, straight, up to 8 pm wide near the base tapering to mostly 3.5-5 pm wide over the fertile part; branching frequently, usually at right angles with branches reflexed slightly toward the apex; primary branches arising in crowded whorls of 3-5, relatively short, usually 2-5 cells long, regularly rebranched; secondary branches in whorls of 2 or 3 , usually 1- or 2-celled; ultimate branches 1-celled, cylindrical or slightly swollen, mostly 4-7 x 3-4.5 pm; upper part of conidiophore main axis branching irregularly just above the fertile part, about 3 p m wide at the fertile part and attenuate to about 0.5 pm wide near the acute apex; the apical part is persistently nonfertile, often branched, narrow, flexuous, or undulate to loosely coiled (Fig. loo), evenly septate with septa 10-22 pm apart, except the apical cell that may be up to 30 pm long and less than 1 pm wide. Phialides ampulliform to lageniform (Fig. 103), mostly 4.0-6.0 x 2.2-3.5 pm, or terminal phialides up to 8 km long; constricted at the base, abruptly narrowed to a very short conidium-bearing tube about 1 pm wide, borne in whorls of 2-4. Conidia ellipsoidal, 3.1- 4.7 X 2.0-2.9 pm (avg. 3.9 x 2.3 pm), both ends broadly rounded or with the base pointed slightly, dilute green, wall smooth (Fig. 106) and relatively thin.

MATERIAL EXAMINED: UNITED STATES: NORTH CARO- LINA: Raleigh: 8- 10 cm depth hardwood forest soil, IV. 1969, R. M. Danielson (DAOM 166162, type culture, = ATCC 28036); L- and F-horizons hardwood forest soil, IV. 1969, R.M.D. (DAOM 166141 = ATCC 28035).

NOTES: Trichoderma pubescens shows affinity to T. hamatum and morphologically similar species having compact, bluish green, hemisphaerical conidiogenous pustules and ellipsoidal conidia of moderate size. From these species it is distinguished by the thin, undulate, branching conidiophore apices, which give the surface of the conidiogenous pustules a characteristic downy appearance.

15. Trichoderma anamorph of Hypocrea semiorbis (Berk.) Berk. (1860), in Hooker, Flora Tasmania, 3(2): 278

Figs. 107-1 1 1 Colonies growing slowly or sparsely on most media, 2.5-

7 cm in diameter after 5 days; the limited aerial mycelium is arachnoid or felty, white. Conidiation lacking or effuse on most media, on malt agar producing irregularly distributed, compact, hemisphaerical pustules up to 2 mm diameter (Fig. 108); glaucous, or greyish in age, from court-grey to gnaphilium green or mineral grey (XLVII). Reverse colourless to yellowish (BLA). Exudate inconspicuous. Odour faintly aromatic, like pine pitch (BLA). Hyphae hyaline, smooth-walled, 1- 10 pm diameter. Chlamydospores very numerous, intercalary or terminal on short branches; elliptical to subglobose, subhyaline to pale greenish, 4- 13 pm diameter, up to 17 p m long;

FIGS. 1 13-120. Trichoderma spirale. Figs. 1 13 and 114. Compact, cushion-shaped conidiogenous pustules, characterized by the conspicuous, coiled conidiophore extensions, on MA after 12 d. DAOM 183974. Fig. 113. x 6. Scale bar = 1 mm. Fig. 114. X 74. Scale bar = 100 pm. Fig. 1 15. Conspicuously coiled conidiophore extensions. DAOM 183974. x 240. Fig. 1 16. Tuberculate roughenings on the conidiophore visible in vapour-fixed, air-dried material. DAOM 183974. x 850. Scale bar = 10 pm. Fig. 117. Longitudinal section through tubercule on conidiophore extension. The tubercule appears empty, and is delineated by relatively diffuse electron dense material, rather than by a discrete membrane. x 21 500. Scale bar = 0.2 pm. Fig. (18. Ampulliform phialides. DAOM 183974. X 1500. Scale bar = 5 pm. Fig. 119. Relatively small, ellipsoid conidia. DAOM 165128. X 1250. Scale bar = 5 pm. Fig. 120. Smooth-surfaced conidia. DAOM 183974. X 8000. Scale bar = 1 pm. Figs. 114, 116, and 120. SEM on material fixed in osmium tetroxide vapour and air-dried. Figs. 1 15, 118, and 1 19. Interference contrast. Fig. 117, TEM on material fixed in gluteraldehyde and osmium tetroxide, and sectioned in Spurr's embedding medium.

wall up to 2 pm thick. Conidiophores hyaline, smooth-walled, relatively coarse and inflexuous, mostly 4.5-7 pm wide over the fertile part; main axis regularly branched over the lower (fertile) part with branches arising singly or more often in pairs or groups of three; branches short, usually 1- to 2-celled and rarely rebranched more than once; upper part of conidiophore nonfertile for 100-200 pm (Fig. log), appearing relatively straight, mostly 3-5 pm wide, sometimes branching and anastomosing just above the fertile part, otherwise unbranched, conspicuously but unevenly septate with septa 3-25 pm apart; the apex broad and rounded or somewhat acuminate in old cultures. Phialides broadly ampulliform, hardly or nor constricted at the base, occasionally arising singly but usually in

whorls of 2-5, mostly 4.7-8.0 x 3.0-4.1 pm (avg. 6.2 X 3.3 pm), tapering to a conspicuous, conidium-bearing tip about 1 pm wide and up to 1.6 pm long. Conidia ellipsoidal to short-cylindrical (Fig. I I I ) , both ends broadly rounded or with the base slightly narrower, mostly 3.0-4.6 x 1.8- 2.7 pm (avg. 4.1 X 2.4 pm), in old cultures up to 5.3 X

3.0 pm; appearing smooth- and thin-walled, subhyaline to greyish.

MATERIAL EXAMINED: NEW ZEALAND: MOHAKA: Hawkes Bay, isolated from Hypocrea semiorbis Berk. on Nothofagus sp., J . M. Dingley (DAOM 167636 = CBS 244.63).

NOTES: The Trichoderma anamorph of H. semiorbis resembles T. longipilis and T. oblongisporum in having elongate,

CAN. 1. BOT. VOL. 69, 1991

FIGS. 121 and 122. Trichoderma strictipilis. Conidiophores ( x 750) and conidia ( X 1500). Fig. 121. DAOM 167072. Fig. 122. DAOM 172827. Type isolate.

greyish conidia. However, the conidia of H. semiorbis are slightly shorter and mostly ellipsoidal rather than parallel-sided as in the other two species. Conidiophores are somewhat less extensively branched in the anarnorph of H. semiorbis, and branches usually shorter. The conidiophore main axis is relatively broad in all three species, but particularly in H. semiorbis, ranging from 4.5-7 pm wide over the fertile part of the conidiophore.

16. Tnchoderma spirale sp. nov. Figs. 112-120 Coloniae celeriter crescentes 4-7 cm diarnetro post 3 dies

(20°C), mycelio in PDA floccoso vel laneo albo vel cineras-

cente, reverso plerurnque flavido vel rufescente. Partes conidiiferae pustulas pulvinatas caesiovirentes usque ad 2.5 rnm diametro facientes. Hyphae hyalinae leves plerumque 1-6 p m latae. ~ h l a m v d o s ~ o r a e abundantes solitahae intekalares vel - L

terminales leves hyalinae vel viridulae subglobosae vel pyriforrnes 5-13 prn diarnetro. Conidiophora hyalina levia aut irregulatim incrassata basi usque ad 8 p m lata pro parte majore 3-5 pm lata parce ramosa, ramis comparate brevibus solitariis aut alternantibus aut binatis, ad apicern crassa per 30-100 p m circinata apice sterilis aut phialide singulari subulata. Phialides 2-6 verticillatae late ampulliforrnes vel subglobosae 3.3-5.2

FIGS. 123-129. Trichoderma strictipilis. DAOM 172827. Type isolate. Figs. 123 and 124. Small, compact, hemispherical conidiogenous pustules on MA afer 12 d. Fig. 123. x 6 . Scale bar = 1 mm. Fig. 124. X40. Scale bar = 200 pm. Fig. 125. Long, straight, nonfertile extensions of the conidiophore main axis. x 200. Scale bar = 20 pm. Figs. 126 and 127. Conidiophore branches with crowded verticils of short, ampulliform phialides. x 500. Scale bars = 10 pm. Fig. 128. Broadly ellipsoid conidia. X 1250. Scale bar = 5 pm. Fig. 129. Conidia, showing smooth surface at high magnifications. x 4300. Scale bar = 2 pm. Figs. 124 and 129. SEM on nonfixed, air-dried material. Figs. 125, 127, and 128. Interference contrast. Fig. 126. Phase contrast.

X 2.8-4.0 pm. Conidia viridia levia ellipsoida vel plus minusve oblonga 3.0-4.4 x 1.8-2.7 pm in capitulis persisten- tibus adhaerentia.

TYPUS e solo isolatus, prope flumen 'Mekong, Thailand', H. B. Schieffer leg. 20.11.1982, DAOM 183974 (pro cultura exsiccata).

Colonies growing rapidly, usually 4-7 cm in diameter after 3 days; aerial mycelium on PDA floccose to woolly, white or greyish. Conidiation mostly in compact, cushion-shaped pustules up to 2.5 mm in diameter (Fig. 113), or concrescent to form concentric or irregular masses; white at first, soon turning blue-green shades near dark bluish glaucous (XLII), pea green, artemesia green, sage green or slate olive (XLVII), in age deep olive grey (LI). Reverse in some isolates colorless, most isolates developing dull-yellowish (MA) to reddish brown (BLA) shades, from ochraceous buff (XV) to cinnamon (XXIX) or cinnamon-brown (XV) in age. Exudate limited, clear, in small droplets in the aerial mycelium (PDA). Odour indistinct or moldy. Hyphae hyaline, smooth-walled, mostly 1-6 pm in diameter, or submerged mycelium up to 12 pm in diameter. Chlamydospores abundant in the submerged mycelium, solitary, intercalary or terminal on short lateral branches, sub-

globose to pyriform, 5-13 pm in diameter, wall smooth, hyaline, about-l pm thick; contents pale greenish. Conidiophores hyaline, smooth-walled or with irregular wall thickenings, 4.5- 8 pm wide near the base, tapering to about 3.5-6 pm wide over most of the length; main axis comparatively little branched, branches relatively short throughout, mostly arising singly, alternately, or paired, not extensively rebranched; ultimate branches 1- or 2-celled, terminal cells cylindrical to barrel-shaped, mostly 4-6 x 4-5 pm; apex of conidiophore stout, 4-5.5 pm in diameter just above the fertile part, tapering abruptly at the acute apex, the terminal cell is narrowly subulate and occasionally fertile in age; the apex is coiled over the last 30-100 pm (Figs. 1 14, 1 15), frequently anastomosing, infrequently branched once or twice, smooth in liquid mounts, but appearing rugose in dissecting microscope observations and in SEM observations on air-dried material (Fig. 116). Phialides broadly ampulliform to nearly subglobose (Fig. 118), mostly 3.3-5.2 x 2.8-4.0 pm, slightly constricted at the base, narrowed abruptly at the apex to a conidium-bearing tube up to 1.5 pm long and about 0.8 pm wide; borne in whorls of 2-6 (mostly 3-4), usually not crowded. Conidia ellipsoid to more or less oblong (Fig. 119), 3.0-4.4

FIG. 130. Trichorlermcr srrigosrrtn. Conidiophore ( x 750) and conidia ( X 1500). DAOM 166121. Type isolate.

x 1.8-2.7 prn (avg. 3.8 x 2.3 pm), both ends broadly rounded, or the base slightly narrower, appearing smooth. at high magnifications (SEM) nearly smooth to minutely rugose (Fig. 120), green, adhering in very persistent aggregates.

MATERIAL EXAMINED: CANADA: ONTARIO: Harrow, field soil, 1977, W. R. Jarvis (DAOM 165 128); isolated from apple root rhizosphere, X. 1985, M. Mansor (DAOM 195151); QUE-

BEC: Gatineau Park, deciduous leaf litter, 9.IX. 1980. J. Bissett and N. Grainger (DAOM 1777 14); COSTA RICA: SAN VITO: premontane rain forest soil, 10.IV. 1979, J. Krug (DAOM 17 19 19); THAILAND: vicinity of Mekong R., bamboo stand soil, 20.11.1982, H. B. Schieffer (DAOM 18397 1 , 183972, 183973, 183974 TYPE culture); UNITED STATES: HAWAII: Oahu, Euculypt~ls sp. leaves on ground, 16.1.1979, M. H. E. Schalkwyk (DAOM 171422); NORTH CAROLINA: Mt. Mitchell, yellow birch stand soil, 30.IV. 1966, R. M. Danielson (DAOM 166134 = ATCC 280 13); Raleigh, 0-2 cm depth loblolly pine stand soil, V. 1969, R.M.D. (DAOM 166142 = ATCC 28040, DAOM 1674 18 = ATCC 26800 = WFPL 230A).

NOTES: Trichodermn spirctle is distinguished by the broad conidiophore elements, compact blue-green pustules, and conspicuous, spiral, sterile conidiophore elongations. Most isolates also are characterized by the conspicuous yellow to reddish brown reverse colour. Trichoderrna fertile also has similarly branched, broad conidiophores, but the conidiophore apex in the latter species is straight and usually bears several short, fertile, branches at the apex.

The conidiophore apex in T. spirule has conspicuous rugose roughenings (Fig. 116) that disappear in liquid microscope mounts. In transmission electron microscope observations

(Fig. 117). these tuberculues appear empty and enclosed by diffuse, electron-dense material. They are not bounded by a membrane as in T. pol~~sporlrl~~ and T . croccllttl.

17. Trichoderrrza strictipilis sp. nov. Figs. 121-139 Coloniae 5-7 cm diametro post 4 dies (20°C). mycelio aerio

sparso in PDA laneo albo, reverso incolorato. ~ a r t e s conidiiferae pustlllas pulvinatas villosas glaucas numerosas usque ad 2.5 mm diametro facientes. Hyphae hyalinae leves plerurnque 1.5-6 pm latae. Chlamydosporae paucae solitariae terminales vel intercalares leves hyalinae vel viridulae ellipsoideae vel subglobosae 5-8 pin diametro. Conidiophora hyalina levia aut basi irregulatim incrassata. basi circa 8 mm lata pro parte rnajore 3.5-5 pm Iata abunde ramosa. ramis principalibus ad basim conidiophorae elongatis. ad apicem recta vel parum flexuosa tenuia per circa 100 pm sterilia apice plerurnque phialide singulari aut 3-4 phialidibus verticillntis. Phialides 3- 6 verticillatae plerurnque arnpulliformes 3.4-7.5 x 2.6- 4.0 pm. Conidia dilute viridin late ellipsoidea 2.8-4.0 x 2.2-3.0 um.

-ruPus ex ascosporis Hypoct-ecr sp. indet. in ligno isolatus "Montreal. Quebec. Canada" G. P. White leg. 20. IX. 1979, DAOM 172827 (pro cultura exsiccata).

Colonies growing moderately, 5-7 crn in diameter after 4 days; mycelium mostly submerged, on PDA with limited. woolly, white mycelium. Conidiation in numerous, small, compact, cushion-shaped to hernisphaerical pustules up to 2.5 mm in diameter (Fig 123), surface appearing hairy due to the presence of very long, relatively straight , conidiophore apices (Fig. 124); pustules often concentrically distributed or concrescent in continuous rings; at first white. soon turning dull-green shades from tea geen to sage green (XLVII). then Russian green (XLII), slate olive or lily green (XLVII). Reverse colourless. Exudate not observed. Odour indistinct. Hyphae hyaline, smooth-walled, mostly 1.5-6 prn in diameter, submerged mycelium up to 9 pm in diameter. Chlamy- dospores few. terminal or intercalary in the submerged mycelium, solitary. ellipsoidal to subglobose, 5-8 prn in diameter: wall smooth. hyaline, less than 1 pm wide; contents subhyaline to pale greenish. Conidiophores hyaline. smooth-walled or with a few irregular wall thickenings near the base, main axis straight, tapering from about 8 pni near the base to 3.5- 5 prn over most of the length, branching dendritically. primary branches arising at right angles, increasing in length toward the base of the conidiophore, usually rebranched several times, ultimate branches I - or 2-celled, terminal cells cylindrical to slightly swollen, mostly 3.6-8.0 x 3.2-4.5 pm; upper part of conidiophore main axis nonfertile for about 100 pm, straight or only slightly flexuous (Fig. 125). relatively thin, tapering from about 3 pm diameter above the fertile part to the acute apex, branched irregularly oncc or twice just above the fertile part; the apical cell usually bears a single, subulate phialide up to 20 pm long and 2-2.5 prn wide. occasionally the apex is sparingly branched or bears a terminal whorl of 3-4 phialides, or there may be a few solitary phialides borne laterally anywhere along the length of the upper portion of the conidiophore main axis. Phialides mostly anipulliform. 3.4-7.5 x 2.6-4.0 pm, constricted at the base. abruptly narrowed to a conidium-bearing tip about 0.8 pm wide and up to 1.4 pm long; mostly arising in crowded whorls of 3-6. Con- idia broadly ellipsoid (Fig. 128), 2.8-4.0 x 2.2-3.0 pm (avg. 3.4 X 2.8 pm), both ends broadly rounded or the base pointed slightly, smooth- and thin-walled (Fig. 129), dilute green.

BISSETT: [ I 241 1

FIGS. 13 1-1 36. Trichoderrnn strigosum. Fig. 13 1 . Compact, hemispherical conidiogenous pustules with "spiny" surface, on BLA after 12 d. DAOM 166121. Type isolate. x 6. Scale bar = 1 mm. Fig. 132 and 133. Straight, acuminate, conidiophore extensions, apex acutely pointed or with a single subulate phialide. DAOM 166121. Fig. 132. X 200. Scale bar = 20 km. Fig. 133. DAOM 166140. X 500. Scale bar = 10 km. Fig. 134. Ampulliform phialides. DAOM 166121. x 1250. Scale bar = 5 km. Fig. 135. Intercalary chlamydospores. DAOM 166121. ~ 2 0 0 . Scale bar = 20 km. Fig. 136. Ellipsoid to short cylindric conidia. DAOM 166140. X 1250. Scale bar = 5 km. Figs. 132, 134, and 135. Interference contrast. Fig. 133. Phase contrast. Fig. 136. Bright field.

MATERIAL EXAMINED: CANADA: ONTARIO: Nepean, Bells Comers, Ulmus americana log, 3.IV. 1980, N. D. Grainger (DAOM 1759296); QUEBEC: Lacolle, isolated from maple forest soil, V. 1976, P. Widden (DAOM 167072); Montreal, isolated from ascospores of Hypocrea sp. indet., from rotting deciduous log, 20.IX. 1979, G. P. White (DAOM 172827 TYPE culture).

NOTES: Trichoderma strictipilis has conidiogenous pustules and a conidiophore branching system similar to T. harnaturn and related species. However, conidia of T. strictipilis are shorter than in T . hamatum. Trichoderma strictipilis also resembles T. fasciculatum, from which it is distinguished by the long, straight to slightly flexuous, sterile conidiophore apices that give the conidiogenous pustules a hairy texture.

18. Trichoderma strigosum sp. nov. Figs. 130-136 Coloniae moderate celeriter crescentes 4-6 cm diametro post

3 dies (20°C), mycelio aerio sparso, in PDA floccoso vel implicate albo, reverso incolorato vel flavido. Partes conidiiferae pustulas hemisphaericas strigosas glaucescentes numerosas usque ad 4 mm diametro facientes. Hyphae hyalinae aut interdum contentis infuscatis leves 2-9 p.m latae. Chlamydos- porae denique abundantes plerumque solitariae interdum catenatae plerumque intercalares hyalinae vel viridulae subglo-

bosae plerumque 5-12 p.m diametro. Conidiophora hyalina levia aut basi irregulatim incrassata, basi usque ad 6 p.m lata pro parte majore 3-4 p.m lata abunde ramosa, ramis principalibus brevibus 2-3 verticillatis ad apicem conidiophori curvatis, parte apicali plerumque recta rigida ad apicem per 50- 100 pm nonramosa et sterili, apice plerumque phialide singulari subulata. Phialides solitariae aut 2-4 verticillatae lageniformes vel ampulliformes 3.8-7.0 x 2.1-3.4 p.m. Conidia viridia levia ellipsoidea vel breviter cylindrica plerumque 3.0- 4.8 x 1.8-2.5 p.m.

TYPUS e solo sylvae isolatus "Sengletary, North Carolina, United States" R. M. Danielson leg. V. 1969, DAOM 166121 (pro cultura exsiccata).

Colonies growing moderately rapidly, 4-6 cm in diameter after 3 days; mycelium mostly submerged, limited aerial mycelium on PDA is floccose or matted, white. Conidiation typically in compact, nearly hemisphaerical pustules up to 4 mm in diameter (Fig. 13 1); pustules numerous, usually concentric or concentrated near the margin of the plate, occasionally concrescent in large masses (PDA), surface appearing prickly or spiny at low magnifications owing to the prescence of conspicuous, stiff, javelin-like, sterile conidiophore apices (especially MA); white at first, soon shading to dull bluish green shades from artemesia green or sage green (XLVII) to

CAN. 1. BOT. VOL. 69, 1991

F I G . 137. Trichoderma tomentosurn. Apical part of conidiophores ( x 750) and conidia ( X 1500). DAOM 178713~. Type isolate

dark porcelain green (XXXIII), and finally near slate olive (XLVII) in age. Reverse colourless to white or dull yellowish in age. Exudate not observed. Odour in some isolates faintly fragrant, like coconut, in other isolates faintly mouldy. Hyphae hyaline or occasionally with brownish contents, smooth-walled, 2-9 pm wide; submerged mycelium up to 14 pm wide. Chla- mydospores abundant in older cultures, mostly intercalary, usually solitary, occasionally in short chains, hyaline to pale greenish, subglobose, mostly 5-12(- 16) pm in diameter, wall hyaline and up to 2.5 pm thick. Conidiophores hyaline, straight and stout, smooth-walled, or occasionally with conspicuous, irregular wall thickenings near the base; up to 6 pm wide near the base, tapering to 3-4 pm wide over the fertile portion, at branch points occasionally swollen to 8 pm diameter; highly branched with primary branches short, mostly 2- to 5-celled, usually arising in whorls of 2 or 3 at acute angles and reflexed toward the apex of the conidiophore, usually highly rebranched; ultimate branches 1- or 2-celled, arising in whorls of 2 or 3; terminal cells nearly cylindrical, 4.5-6.8 x 2.8-3.6 pm; the conidiophore apices are straight, stiff and javelin-like (Fig. 132), rarely somewhat undulate, appearing rugose in dissecting microscope and SEM observations, smooth-walled in liquid mounts; usually branched irregularly 1-3 times just above the fertile part, sterile for 50-100 pm to the apex which usually bears a solitary, unmodified, subulate conidiogenous cell 8-15 pm long and 1-2 p m wide (Fig. 130); conspicuously attenuate from 3-4 pm wide at the

fertile part to about 1 pm wide just beneath the acute apex; inconspicuously and distantly septate with septa 12-26 p m apart. Phialides lageniform to ampulliform (Fig. 134), 3.8- 7.0 x 2.1-3.4 pm, conspicuously constricted at the base, attenuate to a conidium-bearing apex about I pm wide, usually arising in whorls of 2-4, occasionally arising singly. Conidia ellipsoidal to short cylindrical (Fig. 136), variable in size, mostly 3.0-4.8 x 1.8-2.5 pm (avg. 4.1 x 2.1 pm), both ends bluntly rounded, or the base pointed slightly, green, smooth- and thin-walled.

MATERIAL EXAMINED: UNITED STATES: NORTH CARO- LINA: Hofman Forest, 13-15 cm depth forest soil, 20.11.1969, R. M. Danielson (DAOM 166140 = ATCC 28031); Sengle- tary Lake, F-horizon hardwood forest soil, V. 1969, R. M. D. (DAOM 166 12 1 - type culture = ATCC 28042).

NOTES: Trichoderma strigosum appears related to T. hai7zatum and T. pubescens, all three species having compact, bluish green conidiogenous pustules, similar conidiophore branching systems, and narrowly ellipsoidal conidia of moderate size. Trichoderma strigosum is distinguished from the other two species by the straight, javelin-like, sterile conidiophore elongations, giving the conidiogenous pustules a spiny appearance.

19. Trichoderma tomentosum sp.nov. Figs. 137-147 Coloniae moderate celeriter crescentes 4-6 cm diametro post

4 dies (20°C), mycelio in PDA floccoso albo vel cinerascente,

BISSETT: I1 2413

FIGS. 138-147. Trichoderma tomentosum. DAOM 178713~. Type isolate. Fig. 138. Compact, hemispherical conidiogenous pustules with surface appearing hairy, on MA after 12 d. X 6. Scale bar = 1 mm. Fig. 139. Conidiogenous pustule with numerous, coiled conidiophore extensions. X 85. Scale bar = 100 pm. Figs. 140 and 141. Undulate to coiled or circinate, nonfertile extensions of the conidiophores. X200. Scale bars = 20 pm. Fig. 142. Phialides relatively uncrowded, usually paired or 3-verticillate. X 500. Scale bar = 10 pm. Fig. 143. Small, ampullifom phialides. X 1500. Scale bar = 5 pm. Fig. 144. More or less subglobose chlamydospores in submerged mycelium of 40-d-old culture. X 600. Scale bar = 10 pm. Fig. 145. Broadly ellipsoidal conidia. x 1250. Scale bar = 5 pm. Fig. 146. Tuberculate roughenings on apical part of conidiophore in air-dried preparation. x 1700. Scale bar = 5 pm. Fig. 147. Conidia showing smooth surface at high mangnifications. X 8200. Scale bar = 1 pm. Figs. 139 and 146. SEM on nonfixed, air-dried material. Fig. 147. SEM on material fixed in aqueous osmium tetroxide, dehydrated in ethanol.

CAN. J . BOT VOL. 69. 19'11

FIG. 148. Trichoderma virens. Conidiophores ( x 750) and conidia ( x 1500). ATCC 132 13. Type isolate.

reverso incolorato vel pallide flavido. Partes conidiiferae pus- , tulas hemisphaericas tomentosas cinereovirentes usque ad I

6 mm diametro facientes. Hyphae hyalinae leves plerumque 1.5-6 pm latae. Chlamydosporae intercalares vel terminales hyalinae vel viridulae initio paucae breviter cylindricae vel ellipsoideae usque ad 10 x 7 pm, tandem plus abundantes subglobosae vel ellipsoideae usque ad 13 pm diametro. Conidiophora hyalina levia crassa basi usque ad 9 pm lata pro parte majore 3.5-5 pm lata abunde ramosa, ramis principalibus brevibus 2-4 verticillatis, ad apicem circinata sterilia nonramosa. Phialides 3-5 verticillatae ampulliformes vel subglobosae 3.5-5 x 2.5-3.5 pm. Conidia viridia levia late ellipsoidea plerumque 2.5-3.4 x 1.9-2.3 pm.

TYPUS sub cortice Ulmi sp. isolatus "South March, Ontario, Canada" N. Grainger et H. L. Dickson leg. 30.X. 1980, DAOM 1787 13a (pro cultura exsiccata).

Colonies growing moderately rapidly, 4-6 cm in diameter after 3 days; aerial mycelium floccose, white to greyish (PDA). Conidiation mostly in few to numerous, compact, hemisphaerical pustules (Fig. 138), up to 6 mm in diameter (mostly less than 3 mm in diameter); pustules scattered or concentrically arranged, sometimes concrescent into large masses, surface of pustules with a distinctly hairy appearance due to presence of numerous, spiral, sterile conidiophore apical elongations (Fig. 139), which appear roughened at low magnifications; initially dull grey-green, from pea green to celandine green or sage green (XLVII), later near Russian green (XLII), or in age near slate olive to andover green (XLVII) or deep olive grey

(LI); smaller pustules on CDA occasionally in yellowish green shades. Reverse colourless or pale dull yellowish. Exudate colourless, in small droplets in the aerial mycelium (PDA). Odour indistinct. Hyphae hyaline, smooth-walled, mostly 1.5-6 pm in diameter, or submerged mycelium occasionally up to 10 pm in diameter. Chlamydospores few, restricted to the submerged mycelium, intercalary and terminal, hyaline to pale greenish, short-cylindrical to ellipsoidal, up to 10 x 7 pm; wall up to 1 pm thick; very old cultures with chlamyspores more abundant, subglobose to elliptical, up to 13 pm in diameter. Conid- iophores hyaline, smooth-walled or with tuberculate roughening~ near the apex (SEM, Fig. 146) disappearing in liquid mounts; coarse, up to 9 p m wide near the base, narrowing to 3.5-5 pm wide through the fertile part, highly branched; primary branches short, 2-4 cells long; branches arising in verticils of 2-4, final branches mostly I-celled, swollen or barrel- shaped, mostly 4-7.5 x 3-5 pm; the conidiophore main axis has a conspicuous, sterile, upper part that usually branches several times just above the fertile part and anastomoses frequently with adjacent conidiophores; strongly coiled or circinate near the apex (Figs. 137, 141), evenly septate (17-26 pm distant), narrowing from 3-4.5 pm near the fertile part to about 1.5 pm near the apex that is usually bluntly rounded, in age the much-branched conidiophore develops narrow, acuminate apices. Phialides ampulliform to subglobose (Fig. 143), mostly 3.5-5 x 2.5-3.5 pm, constricted at the base and abruptly narrowed at the apex to a conspicuous conidium bearing tip about 0.5 pm wide and up to 1.2 pm long, arising in

BISSE'IT: 11 2415

FIGS. 149-155. Trichoderma virens. Fig. 149. Effuse conidiation, with conidia aggregating in mucoid heads, on BLA after 12 d. DAOM 167651 ex ATCC 13213. Type isolate. x 6. Scale bar = 1 mm. Fig. 150. Apical part of conidiophore with branches arising irregularly near the apex. X 500. Scale bar = 10 pm. Fig. 151. Large, ampullifom phialides appressed in terminal verticils on nearly cylindrical branches. x 1250. Scale bar = 5 pm. Fig. 152. Subglobose chlamydospores, occasionally with very thick walls. X 600. Scale bar = 10 pm. Fig. 153. Broadly ellipsoid to obovoid conidia. x 1250. Scale bar = 5 pm. Fig. 154. Conidial balls developed from terminal phialide verticils. x 1700. Scale bar = 5 pm. Fig. 155. Conidia with warted surface apparent at high magnification. X 8500. Scale bar = 1 pm. Figs. 150-155. DAOM 167419. Figs. 150-153. Interference contrast. Fig. 154. SEM on osmium tetroxide vapour-fixed, air-dried material. Fig. 155. SEM on material fixed in osmium tetroxide vapour with two additional layers liganded with hydrazine hydrate, and air dried.

whorls of 3(-5). Conidia broadly ellipsoid (Fig. 145), mostly 2.5-3.4 x 1.9-2.3 pm (avg. 3 .O-2.1 pm), both ends broadly rounded, wall smooth and relatively thin, green.

MATERIAL EXAMINED: CANADA: BRITISH COLUMBIA: Agassiz, isolated from roots of tomato grown in sawdust, J . G. Menzies & C. Koch (DAOM 212357,212358); Manitoba, isolated from sclerotia on lodged sunflower plant (Helianthus annuus L.), 1987, H. C. Huang (DAOM 21 1960); ONTARIO: South March, Ulmus sp. under bark, 30.X. 1980, N. Grainger & H. L. Dickson (DAOM 178713a, type culture); QUEBEC: Cantley, Pinus sp. branch, 21.1X.1980, H.L.D. (DAOM 177748~); Ulmus sp. log, 21.1X.1980, N.G. & H.L.D. (DAOM 177747a,b); UNITED STATES: NORTH CAROLINA:

Raleigh, coniferous forest soil, V. 1969, R. M. Danielson (DAOM 165781 = ATCC 28041); OREGON: Columbia Co., Pseudotsuga menziesii roots and stumps infested with Phelli- nus wierii, IX.1983, E. Nelson EN92, EN198 (DAOM 195049, 195050).

NOTES: Trichoderma tomentosum is differentiated from other species producing compact, grey-green, hemisphaerical conidiogenous pustules by the small conidia (less than 3.5 X

2.5 pm). Trichoderma minutisporum has similar conidia, but produces spreading,flat, bright green conidiogenous pustules. The conidiophore in T. tomentosum has a conspicuous, coiled to circinate, nonfertile elongation, whereas the conidiophore main axis in T. minutisporum is straight, branched and fertile

24 16 CAN. J . BOT. \

to the apex. Tuberculate roughenings on the conidiophore apex in T. tomentosum disappear in liquid mounts.

20. Trichodernza virens (Miller, Giddens & Foster) von Arx, Nova Hedwigia Beih. 87: 288. 1987 Figs. 148- 155

=Gliocladi~lm virerzs Miller, Giddens & Foster, Mycol. 49: 792. 1957

Colonies growing rapidly, 8-9.5 cm in diameter after 4 days (slightly slower on PDA); aerial mycelium floccose, white to greyish. Conidiation may be predominately effuse (Fig. 149) covering the entire surface of the plate, or form spreading, flat pustules concentrated near the margin of the plate or arranged concentrically; quickly turning dark bluish green from pistachio green, American green or leaf green to dull blackish green (XLI), or dusky dull green (XLII) in age. Reverse colourless, or slowly developing dull yellowish to arnber shades (especially BLA). Exudate lacking. Odour indistinct. Hyphae hyaline, smooth-walled, mostly 1.5-6 pm wide, or submerged mycelium up to 10 pm wide. Chlamydospores abundantly produced, especially in the submerged mycelium (Fig. 152); terminal or intercalary, usually solitary, subglobose to ellipsoidal, mostly 6- 12 x 5-9 pm, but up to 22 p m in diameter in older cultures, subhyaline to pale green; wall smooth and usually about 1 pm thick, but occasionally up to 4 pm thick. Conidiophores subhyaline, smooth-walled, in areas of effuse conidiation arising as lateral branches from undifferentiated aerial mycelium, commonly 30-300 pm long, 2.5-5 pm in diameter, toward the base frequently sterile and unbranched for about half the length, or with one or two fertile branches; toward the apex branching irregularly with each branch terminated by a cluster of 3-6 closely adpressed phialides (Fig. 150); macronematous conidiophores more complex, up to 7 pm wide in the lower part, tapering to 4-6 pm wide; branching irregularly, the upper part fertile to the apex without a sterile region, the apex frequently bearing a terminal whorl of adpressed branches and phialides; branches arising at right angles or reflexed toward the apex, primary branches usually arising singly or in opposite pairs immediately beneath septa, rebranched irregularly once or twice; ultimate branches 1- or 2-celled, cylindrical or slightly swollen, mostly 6-18 x 3- 4 pm; entire branching system irregular and uncrowded. Phialides from complex conidiophores lageniform to ampulliform (Fig. 151), mostly 4.5-lo(-13) x 2.8-5.5 pm, constricted at the base, swollen in the middle, attenuate to the apex that is 1-2 pm wide and broadly attached to the conidia; mostly arising in closely appressed verticils of 2-5 on terminal branches, occasionally solitary or in pairs laterally on the conidiophore and branches; phialides from effuse areas of conidiation lageniform to subulate, up to 20 pm long x 2.5- 3 pm. Conidia broadly ellipsoidal to obovoid (Fig. 153), mostly 3.5-6.0 x 2.8-4.1 pm (avg. 4.4 x 3.5 pm), both ends broadly rounded or with the base narrower or apiculate; appearing smooth-walled (minutely warted at high magnifications, Fig. 155), dark green, conidia from adjacent phialides often coalescing into large gloeoid masses (Fig. 154).

MATERIAL EXAMINED: CANADA: ONTARIO: London, Scler- otinia sclerotiorum (Lib.) de Bary sclerotia on white bean, VIII. 1978, J . C. Tu (DAOM 169262); NEW ZEALAND: MOHAKA, 1957. J . M. Dingley (DAOM 167417 = WFPL 231B); UNITED STATES: GEORGIA: Bleckley Co., cultivated soil, 6.1.1956, J . E. Giddens 167 (DAOM 16765 1 = ATCC 13213 - type culture); OHIO: isolated from muck soil, L. Mihuta (DAOM 195132); OREGON: Columbia Co., Pseu-

dotsuga rnerzziesii stumps and roots infested with Phellirzus wierii, IX.1983, E. Nelson EN-27 (DAOM 195048); Pringle Falls Experimental Forest near Bend, isolated from soil, 1983. J . Reaves (DAOM 196543); Rainier, decayed roots of Pseu- dotsugn menziesii, E . Nelson (DAOM 195 133, 195 134). UNKNOWN LOCALITY: (DAOM 16741 9 = WFPL 161H = BKMF 11 17, DAOM 167647 = WFPL 258A, DAOM 167648 = WFPL 258B, DAOM 167653 = ATCC 9645 = QM 365 = NRRL 23 14).

NOTES: Trichoderma virens is characterized by the large, obovoid conidia, and predominantly effuse conidiation, with conidiophores broad, sparingly branched, and fertile to the apex. Trichoderma crussum and T . jlnvofuscum are morphologically similar, but the latter species have conidiophores mostly aggregated in flat, spreading pustules. In addition, T. flavofuscum has brown rather than green conidiation, and T . crussum has a nonfertile conidiophore elongation that is lacking in T . virens.

Acknowledgements

The curators of ATCC (Rockville), CBS (Baarn), IMI (Kew), and WFPL (Vancouver) graciously provided specimens and cultures on loan. I thank Mr. S. J . Darbyshire for assistance in culturing fungi, photography, plate preparation, and electron microscopy, and Ian A. MacLatchy for inking the figures. The author is grateful to the Biographics Unit, Research Program Services, and the Electron Microscope Unit, Plant Research Centre, Agriculture Canada, for the use of their facilities.

ABBOTT, E. V. 1926. Taxonomic studies on soil fungi. Iowa State Coll. J . Sci. 1: 15-36.

BAINIER, M. G. 1906. Mycothkque de I'Ccole de pharmacie. 111. Bull. Trimest. Soc. Mycol. France, 22 : 130-133.

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