T A N E 21, 1975

THE VEGETATION OF THE MT MAUNGATAWHIRI AREA, COROMANDEL PENINSULA

by A .E . Wright*

SUMMARY The major vegetation types for the area surrounding Mt Maungatawhiri,

Coromandel Peninsula, are discussed, and their distribution is mapped. A species list of 253 vascular plants is presented. The vegetation is dominantly coastal and ranges from estuarine and rocky shore to mature rata {Metrosideros robusta) forest 300m above sea level. Much of the area has been extensively modified by man through farming, accidental burning and selective milling, although pockets of forest apparendy undisturbed by man do exist on the eastern slopes of Mt Maungatawhiri itself.

INTRODUCTION These observations were made during the AUFC Scientific Camp to

Wharekaho Beach, Whitianga ( 1 7 - 2 4 August, 1974). It is hoped that they will provide adequate information for future comparisons between the floras of the larger offshore islands of the Coromandel Peninsula and those of the mainland. Therefore, particular emphasis has been placed on the indigenous flora, and those adventive species which play an important part in each vegetation type. Each major vegetation grouping is briefly discussed mentioning important and unusual species, and its distribution shown in Figure 1, together with the typical localities later described.

The lichen flora of this area has been studied in detail by Hayward et al.s

VEGETATION Estuarine: The estuary of the Akeake River curves back behind Wharekaho Beach to form an area of low silty banks. The plant cover of these banks varies with the frequency of inundation by salt water. The main bank is largely covered by clumps of Juncus maritimus var. australiensis and Scirpus nodusus with a few shrubby Plagianthus divaricatus and manuka (Leptospermum scoparium). Lower areas are sparsely covered in the creeping grass Cynodon dactylon. Coastal forest and shore: Most cliff areas retain a largely natural vegetation similar to that in other areas of the Coromandel Peninsula. Tree species include pohutakawa {Metrosideros excelsa), karaka (Corynocarpus laevigatus), taupata (Coprosma repens), kawakawa (Macropiper excelsum), and kohekohe (Dysoxylum spectabile) with a groundcover of flax (Phormium tenax), Astelia banksii and the herbs Peperomia urvilleana, Apium australe and Disphyma australe. Bare soil on the foreshore provides a habitat for sowthistles (Sonchus spp.), catsear (Hypochaeris radicata), and Oxalis sp., with the natives NZ Convolvulus (Calystegia tuguriorum), Mercury Bay weed (Dichondra repens) and piripiri (Acaena anserinifolia) spreading back into the pastures. Many of the *Department of Geology, University of Auckland

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Fig. 1. Map of the area surrounding Mt Maungatawhiri showing distribution of major vegetation types and location of the typical localities described in the introduction to the species list.

stream valleys running inland through pasture have remnant coastal forest in their headwaters. Large puriri, (Vitex lucens) kohekohe and karaka formed the canopy, with almost all ground cover (except occasional tangles of supplejack — Ripogonum scandens) eaten out by cattle and sheep. The orchid Drymoanthus adversus was found in bud several times, epiphytic on karaka trees. Summit ridge of Mt Maungatawhiri: Between the main peak of Mt Maungata­whiri and the slightly lower knoll to the southsoutheast (see Fig. 1) runs a fairly sharp ridge dropping very steeply to the east and sloping down more gently to the west. The two high points appear to have been burnt off within the last twenty years and the trees on the flat area surrounding the trig have been cut down much more recently. The fallen branches have provided shelter for dense regeneration of shrubs 2 to 3m tall, for example pohutakawa and mapou (Myrsine australis). Between the knolls, the ridge proper has a mature canopy dominated by mahoe {Melicytus ramiflorus), puriri and karaka with few shrub species beneath them. Towards the south, the ground becomes more rocky, and ferns are the most common ground dwelling plants. The necklace fern (Asplenium flabellifolium), velvet fern (Ctenitis velutina) and Arthropteris tenella were all found only in this area. Arthropteris covers almost all boulders, roots and tree trunks over a large area. It exhibits the usual distinct difference between small, sterile, terrestrial fronds forming a dense covering over the substrate, and larger (up to 30cm) fertile fronds epiphytic on tree trunks. Where the canopy is thinner, the native grass Oplismenus imbecilis is abundant. Mature rata forest: Although some tracts have been selectively milled, a few areas appear to be in their virgin state (no old stumps or adventive species were seen). Many of the stream valleys to the west of Mt Maungatawhiri contain very dense forest with a wealth of ferns and shrubs. Filmy ferns are especially common, and over several hundred metres of one stream Hymenophyllum flexuosum is the dominant filmy fern, always rupestral. Treeferns, predomin­antly mamaku {Cyathea medullaris) are frequent in stream valleys and large stretches of these valleys are choked with supplejack. Large rata are dominant in the drier parts, forming the canopy with common rewarewa (Knightia excelsa) and karaka. Beneath these are several species of Coprosma and the NZ Honeysuckle (Alseuosmia macrophylla). Leptospermum scrub: Along the southern fringe of the mature rata forest is a belt of 20 to 30 year old manuka (Leptospermum scoparium) and kanuka (L. ericoides). Grazing animals, including cattle, have entered the scrub and opened up the shrub layer. Occasional manuka and kanuka have been knocked over, and the greater light penetration has allowed thicker seedling growth. The majority of ground cover is formed by lycopods, the ferns Lindsaea linearis and Phymatodes diversifolium, sundew (Drosera auriculata), mapou seedlings and various adventive weeds such as Hypochaeris, Erigeron and Cirsium vulgare. Further to the northwest, regeneration is at a more advanced stage, and less held back by interference by grazing animals. Consequently, the flora is considerably more diverse. The climbers Clematis paniculata and bush lawyer (Rubus cissoides) are common and there are many healthy saplings of kauri (Agathis australis), rimu (Dacrydium cupressinum) and tanekaha (Phyllocladus trichomanoides) up to 3m tall. It is interesting to note that kauri did not occur in the

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forest or scrub to the east of Mt Maungatawhiri (apart from one unhealthy tree below the summit of the main hill) — it only became common in the north east i.e. more inland. Pasture: Pasture areas provide the best hunting ground for adventive species. Many such as the barberry (Berberis sp.), wooly mullein (Verbascum thapsus), foxglove (Digitalis purpurea), nettle (Urtica mens) and Californian and Scotch thistles (Cirsium arvense and C. vulgare) occur over most of the area and are a considerable nuisance to the farmers. Around streams blackberry (Rubus fruticosus Agg.) and fleshy weeds such as inkweed (Phytolacca octandra) are common. In the streams grow a few water-weeds such as the floating sweet grass (Glyceria fluitans), watercress (Nasturtium officinale) and duckweed (Lemna sp.).

Several large colonies of the fern Hypolepis tenuifolia (the smaller, triangular fronded type) occur in depressions in the pastures and these appear to be untouched by grazing animals just as the adventive noxious weeds are. In one area, the fern Athyrium australe occurs commonly in the damp pasture.

Remnants of the forest cover such as ancient puriri and one old ngaio (Myoporum laetum) dot the pastures, as do rotting treefern stumps in several areas (lichen zonation on these stumps has been studied by Hay ward et als).

The scrambling pohuehue (Muehlenbeckia complexa) is common in coastal pastures, most noticeably on the summit of the pa (Fig. 1) described by Puch. 9

There it forms cushions up to 50cm thick which are cut through by grassed animal trails. Swampy areas: Swamps have formed in several basins to the South and East of Mt Maungatawhiri, particularly where soil cover has slumped off the rock basement to block off a valley. Dominant plants are the raupo (Typha orientalis) and Scirpus lacustris, with the water fern Histiopteris incisa occuring around the margins of the swamps.

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SPECIES LIST OF V A S C U L A R PLANTS Both native and adventive species are included. While the coverage of the

former was fairly thorough, the adventive flora is incomplete, largely consisting of those species that play an obvious part in the communities already described. The total flora listed comprises 253 species, of which 196 species (78%) are indigenous to New Zealand. 59 of the native species are ferns and fern-allies.

Nomenclature and ordering for all native plants except grasses follows Volumes 1 and 2 of 'Flora of New Zealand'. 1 ' 7 Native grasses follow Cheeseman.2

Exotic species (marked with asterisk) are named largely from Clapham, Tutin and Warburg (Flora of the British Isles);3 and exotic, non-European grasses from Lambrechtsen.6 Well known common names are given, and where applicable follow 'Standard Common Names for Weeds in New Zealand'. 1 0

Each of the habitats and its community (already described) has been designated a number and a typical locality: 8

Loc. 1. Estuary of Akeake River, Mercury Bay N44 223678 0 - l m above sea level.

Loc. 2. Coastal forest, cliff and shore vegetation, Mercury Bay N44 237678 0-10masl.

Loc. 3. Summit ridge of Maungatawhiri Mt, Whitianga N44 232687 approx. 300m asl.

Loc. 4. South western slopes of Maungatawhiri Mt, Whitianga (a) mature rata forest N44 228689 160m asl (approx.). (b) Leptospermum fringe N44 230684 120m asl (approx.).

Loc. 5 (a) pasture to Southeast of Maungatawhiri Mt. (b) pasture around streams (c) pools in streams in pasture N44 236688 100m asl (approx.).

Loc. 6. Swampy areas to Southeast of Maungatawhiri Mt. N44 234688 150m asl (approx.).

The area studied centred on the latitude and longitude 36° 47'S 175° 47'E. Beside each species is the number of the habitat(s) in which it is most commonly found.

Specimens of all ferns and fern allies are held in the author's Herbarium; specimens of most other plants are held in the Herbarium of the Auckland Institute and Museum.

* : adventive t : planted

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PSILPOSIDA Psilotaceae LYCOPSIDA Lycopodiaceae

FILICOPSIDA Osmundaceae Schizaeaceae Hymenophyllaceae

Dicksoniaceae Cyatheaceae

Polypodiaceae

Grammitidaceae Thelypteridaceae Dennstaedtiaceae Lindsaeaceae

Davalliaceae Pteridaceae

Aspleniaceae

Blechnaceae

Tmesipteris tannensis

Lycopodium billardieri L. deuterodensum L. volubile

Todea hymenophylloides Lygodium articulatum

Hymenophyllum flabellatum H. dilatatum H. rarum H. sanguinolentum H. demissum H. flexuosum H. revolution H. multifidum Trichomanes venosum T. endlicheriana T. elongatum T. reniforme Dicksonia squarrosa Cyathea dealbata C. medullaris Pyrrosia serpens Phymatodes scandens P. diversifolium Grammitis ciliata Thelypteris pennigera Hypolepis tenuifolia Lindsaea linearis I. , cuneata Arthropteris tenella Paesia scaberula Histiopteris incisa Pteridium aquilinum var.

esculentum Pteris tremula P. macilenta Asplenium flabellifolium A. lucidum A. falcatum A. lamprophyllum A. bulbiferum A. flaccidum Doodia media

clubmoss clubmoss clubmoss

heruheru mangemange filmy ferns

kidney fern wheki ponga mamaku

scented fern hound's tongue

scented fern

bracken

necklace fern shining spleenwort

hen & chickens makawe

4(a)

4(a) 4(b) 4(b)

4(a) 4(a)

4(a) 4(a) 4(a) 4(a) 4(a) 4(a) 4(a) 4(a) 4(a) 4(a) 4(a) 4(a)

4.5(b)

2,4,5(b) 4,5(b)

2,3,4(b) 4(a)

2,3,4 4(b) 4(a) 5(a) 4(b) 4(a) 3

2,5(a) 6

5(a) 5(b) 4(a) 3 4(a) 4(a) 3 4(a) 4(a) 3

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Blechnum fraseri 4(a) B. filiforme 4(a) B. capense kio kio 4(a) B. discolor crown fern 4(a) B. lanceolatum 4(a) B. membranaceum 4(a) B. fluviatile 4(a)

Dryopteridaceae Polystichum richardii 3 Ctenitis glabella 4(a) C. velutina velvet fern 3 Rumohra hispida hairy fern 4(a)

Athyriaceae Athyrium australe 5(b) Adiantiaceae Adiantum hispidulum maidenhair 3

A. cunninghamii maidenhair 3.4(a) A. fulvum maidenhair 3.4(a) Cheilanthes distans 5(a) Pellaea rotundifolia 3

SPERMATOPSIDA : GYMNOSPERMAE Podocarpaceae Podocarpus ferrugineus miro 4(a)

P. totara totara 4 Dacrydium cupressinum rimu 4(a) Phyllocladus trichomanoides tanekaha 4

Araucariaceae Agathis australis kauri 4 Pinaceae Pinus radiata* radiata pine t

P. pinaster* maritime pine t P. ?oocarpa* t

Cupressaceae Cupressus macrocarpa* macrocarpa t ANGIOSPERMAE : DICOTYLEDONES

Lauraceae Beilschmiedia tawa tawa 4(a) Monimiaceae Hedycarya arborea pigeonwood 4(a) Ranunculaceae Clematis paniculata clematis 2,4 Berberidaceae Berberis sp.* barberry 5(b) Piperaceae Macropiper excelsum kawakawa 4(a)

Peperomia urvilleana 4(b) Cruciferae Cakile edentula* sea rocket 2

Nasturtium officinale* watercress 5(c) Violaceae Melicytus ramiflorus mahoe 4(a) Droseraceae Drosera auriculata sundew 4(b) Aizoaceae Disphyma australe iceplant 2

Tetragonia trigyna NZ Spinach 2 Caryophyllaceae Cerastium glomeratum * chickweed 5(a)

Sagina apetala* annual pearlwort 2 S. procumbens* pearlwort 2 Scleranthus biflorus 5(a) Spergularia arvensis* spurrey 2.5(a) Stellaria media* chickweed 5(a)

Phytolaccaceae Phytolacca octandra* inkweed 5(b)

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Polygonaceae Muehlenbeckia australis pohuehue 4(b) M. complexa pohuehue 5(a) Polygonum persicaria* willow weed 5(a) Rumex acetosella* sheep's sorrel 5(a)

Geraniaceae Geranium molle* dove's foot 5(a) Oxalidaceae Oxalis corniculata 5(a) Linaceae Linum sp.* 5(a) Haloragaceae Haloragis erecta shrubby haloragis 4(b) Onagraceae Epilobium rotundifolium 5(b)

Fuschia excorticata kotukutuku 5(b) Callitrichaceae Callitriche stagnalis star wort 5(c) Proteaceae Persoonia toru toru 4(a)

Knightia excelsa rewarewa 4(a) Hakea sericea * hakea 4(b)

Coriariaceae Coriaria arborea tutu 4(a) Pittosporaceae Pittosporum virgatum 4(b)

P. tenuifolium kohuhu 4(b) P. crassifolium karo 2 P. umbellatum 4(b) P. eugenioides tarata 4(b)

Myrtaceae Leptospermum scoparium manuka 4(b),5(a) L. ericoides kanuka 4(b) Metrosideros excelsa pohutakawa 2,3 M. robusta tree rata 4(a) M. fulgens rata vine 4(a) M. carminea carmine rata 5(a) M. perforata clinging rata 5(a)

Tiliaceae Entelea arborescens whau 2 Malvaceae Plagianthus divaricatus marsh ribbonwood 1

Hoheria populnea houhere 3 Euphorbiaceae Euphorbia peplus * milkweed 2 Cunoniaceae Weinmannia racemosa kamahi 4(a) Escalloniaceae Quintinia serrata tawheowheo 4(a)

Ixerba brexioides tawari 4(a) Rosaceae Rubus australis bush lawyer 3

R. cissoides bush lawyer 3 R. fruticosus Agg.* blackberry 1.5(b) Rosa rubiginosa* sweet briar 5(b) Acaena anserinifolia piripiri 5(a)

Leguminosae Lupinus arboreus* tree lupin 2 Trifolium repens* white clover 5(a)

Papilionaceae Sophora microphylla kowhai 2 Carmichaelia cunninghamii NZ broom 2 Lotus subbiflorus* lotus hispidus 5(a)

Moraceae Paratrophis banksii large-leaved milk tree 2 P. microphylla milk tree 4(b)

Urticaceae Elatostema rugosum parataniwha 4(a)

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Urtica urens* nettle 5(a) Corynocarpaceae Corynocarpus laevigatus karaka 3.4(a) Rhamnaceae Pomaderris phylicifolia

var. ericifolia tauhinu 5(a) Rutaceae Melicope ternata wharangi 2 Meliaceae Dysoxylum spectabile kohekohe 2 Sapindaceae Alectryon excelsus titoki 3

Dodonaea viscosa akeake 2 Araliaceae Schefflera digitata pate 4(a)

Neopanax arboreus4 five finger 4(a) Pseudopanax crassifolius lancewood 4(a)

Cornaceae Griselinia lucida puka 4(a) Umbelliferae Centella uniflora centella 2

Apium australe NZ celery 2 Lilaeopsis orbicularis 1

Epacridaceae Cyathodes fasciculata mingimingi 4(b) Dracophyllum latifolium neinei 4(a)

Myrsinaceae Myrsine australis mapou 4(a) Oleaceae Nestegis lanceolata white maire 4(b)

N. montana mountain maire 4(b) Oka europaea * olive 1

Loganiaceae Geniostoma ligustrifolium hangehange 4(a) Apocynaceae Parsonsia heterophylla kaiwhiria 3

Vinca major* periwinkle 2 Caprifoliaceae Alseuosmia macrophylla NZ honeysuckle 4(a) Rubiaceae Coprosma Areolata 4(a)

C. rhamnoides 5(a) C. spathulata x rhamnoides 4(a) C. spathulata 4(a) C. arborea mamangi 4(a) C. australis raurekau 2.4(a) C. robusta karamu 2.4(a) C. repens taupata 2 Galium parisiense * slender bedstraw 5(a)

Compositae Olearia rani heketara 4(b) O. albida Auckland tree daisy 4(b) Cotula coronopifolia batchelor's button 2 C. australis 2 C. dioica 2 Gnaphalium luteo-album Agg. cudweed 5(a) Senecio kirkii Kirk's tree daisy 4(b) S. minima 5(a) S. jacobea* ragwort 5(a) Brachyglottis repanda rangiora 4(a) Picris echioides* oxtongue 2 Sonchus littoralis shore sowthistle 2 S. oleraceus* sowthistle 2.5(a)

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Primulaceae

Plantaginaceae Goodieniaceae Lobeliaceae Solanaceae

Convolvulaceae

Scrophulariaceae

Gesneriaceae Myoporaceae Verbenaceae

Avicenniaceae Labiatae Orobanchaceae

Juncaginaceae Liliaceae

Smilaceae Agavaceae

Lemnaceae Juncaceae

Restionaceae Typhaceae Iridaceae Palmae Pandanaceae Orchidaceae

Crepis capillaris* Taraxacum officinale* Circium vulgare* C. arvense* Hypochaeris radicata* Bellis perennis*

Erigeron floribundus* Eupatorium adenophorum * Samolus repens Anagallis arvensis* Plant ago major* Selliera radicans Lobelia anceps Solatium laciniatum S. nigrum* Calystegia tuguriorum Dichondra repens Hebe stricta var. stricta H. macrocarpa Verbascum thapsus* Digitalis purpurea * Rhabdothamnus solandri Myoporum laetum Vitex lucens Verbena bonariensis* Avicennia resinifera Mentha pulegium* Orobanche minor* MONOCOTYLEDONES Triglochin striatum Arthropodium cirratum Astelia banksii Collospermum hastatum Ripogonum scandens Cordyline australis Phormium tenax Lemna ?minor* Juncus maritimus var.

australiensis J. pallidus J. sp. Leptocarpus similis Typha orientalis Liber tia grandiflora Rhopalostylis sapida Freycinetia banksii Acianthis fornicatus var. sinclairii

hawksbeard dandelion Scotch thistle Calif, thistle catsear lawn daisy

broad leaved fleabane Mexican devil

scarlet pimpernel plantain remuremu shore lobelia poroporo black nightshade NZ convolvulus Mercury Bay weed koromiko

wooly mullein foxglove waiuatua ngaio puriri purple-top mangrove penny royal broom rape

renga lily

supplejack cabbage tree flax duckweed

sea rush rush

jointed rush raupo

nikau kiekie

2 2.5(a)

5(a) 5(a)

2.5(a) 5(a)

5(a). 4(b) 2 5(a) 5(a) 2 2

2.5(b) 5(b) 2 2 4(a) 4(a) 5(a) 5(a) 4(a) 5(a)

4(a),5(a) 5(a) 1

5(a) 5(a)

2 2

2.4(a) 4(a) 4(a)

l,2,4(a),6 1,2

5(c)

1,2 6 5(a) 6 6 3 4(a) 4(a) 4(a)

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Corybas rivularis 4(a) Thelymitra sp. 4(a) Pterostylis trullifolia 4 P. banksii 4(a) Earina mucronata 4(a) E. autumnalis 4(a) Dendrobium cunninghamii 4(a) Bulbophyllum pygmaeum 4(a) Drymoanthus adversus 2

Cyperaceae Cyperus ustulatus 1,2 Scirpus lacustris 6 5. nodosus 1,2 5. cernuus 2 Gahnia lacera 2 Desmoschoenus spiralis pingao 2

Gramineae Holcus lanatus* Yorkshire fog 5(a) Zoysia sp. 1 Cynodon dactylon* Indian doab 1,2 Oplismenus undulatifolius 3 Sporobolus africanus* ratstail 1,2,5(a) Stenotaphrum secundatum* buffalo grass 1,2,5(a) Stipa teretifolia needle grass 1 Festuca arundinacea* tall fescue 5(a) Paspalum dilatatum* paspalum 1.5(a) Glyceria fluitans* floating sweetgrass 5(c) Poa annua* 5(a) Lagurus ovatus* harestail 2 Pennisetum clandestinum* kikuyu 2

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ACKNOWLEDGEMENTS I wish to thank Messrs Geoffrey Body and David Court for assistance in

the field; Mr Court and Mr J.E. Braggins for discussion and critical reading of the manuscript; and members of the Botany Department of the Auckland Institute and Museum for their help with the identification of adventive species.

REFERENCES 'Allan, H.H. 1961: 'Flora of New Zealand' Volume 1. Government Printer,

Wellington. 2Cheeseman, T.F. 1925: 'Manual of the New Zealand Flora' 2nd ed.

Government Printer, Wellington. 3Clapham, A.R.; Tutin, T.G.; Warburg, E.F. 1962: 'Flora of the British Isles'

2nd ed. Cambridge University Press. "Edgar, E. 1973: Names in Pseudopanax C. Koch (Araliaceae). N.Z.J. Bot. 11:

171-172. 5Hayward, B.W.; Hayward, G.C.; Galloway, D.J. 1975: Lichens from Northern

Coromandel Peninsula, New Zealand. Tane 21 (this issue). 6Lambrechtsen, N.C. 1972: 'What grass is that? NZ DSIR Information series

No. 87. Government Printer, Wellington. 7Moore, L.B.; Edgar, E. 1970: 'Flora of New Zealand' Volume 2. Government

Printer, Wellington. 8 N Z M S 1. Whitianga Sheet N44 (4th Edition, 1972) Lands and Survey

Department. Government Printer, Wellington. 9Puch, G.F. 1975: Some Archaeological Sites from the Mount Maungatawhiri

Area, North Whitianga. Tane 21: (this issue). 10'Standard Common Names for Weeds in New Zealand', 1969. New Zealand

Weed and Pest Control Society. Editorial Services, Wellington.

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