The Monocots: Part 1Overview, Basal, and “Petaloid” Groups
Spring 2014
Figure 7.1 from the text
Synapomorphies of Monocots• Root system adventitious • One cotyledon • Stems with scattered vascular bundles (no
secondary growth); herbaceous• Leaves parallel-veined with a sheathing
base• Flowers pentacyclic (5 whorls), trimerous • Sieve tube member plastids with several
cuneate protein crystals• Lots of molecular support for monophyly
Monocot charactersAdventitious roots:
-derived from structures other than another root
Monocot characters• One cotyledon!
MONOCOTNON-MONOCOT
Monocot charactersScattered vascular bundles in stem
– numerous; actually complex organization– no vascular cambium (a few weird exceptions)
Monocot charactersLeaves:
– parallel venation in most monocots [may be reversals with net-venation!]
– sheathing base
Trillium
Smilax
Monocot characters
• Pentacyclic, trimerous flowers with 2 perianth whorls and 2 whorls of stamens and the gynoecium as 1 whorl
Monocot charactersCuneate protein bodies in sieve cell plastids
– “wedge-shaped” inclusions– function unknown
Additional features of monocots
• Leaves formed from the basal end of the leaf primordium
• Usually with monosulcate pollen• Lack glandular teeth on leaves
How many monocots?• ca. 3,000 genera• ca. 65,000 species • 22-25% of angiosperms• Include:
-aroids-bananas-lilies-gingers-orchids (20,000+ spp.)-irises-palms-grasses (11,000+ spp.)
Fig. 7.17 from Simpson
Phylogeny of Monocot GroupsAcoralesAlismatalesLilialesAsparagalesDioscorealesPandanalesArecalesPoalesCommelinalesZingiberales
Basal“Petaloid”Commelinid
Basal and “Petaloid” Monocot GroupsOrder Acorales
Acoraceae
Order AlismatalesAraceae*
Alismataceae
Order LilialesLiliaceae*
Order AsparagalesAgavaceae Alliaceae*AmaryllidaceaeIridaceae*Orchidaceae*
*required families
Basal Monocots:Acorales: Acoraceae
• Widespread, temperate throughout tropical regions
• Aquatic herb• Diversity: 1-3 spp. in 1 genus (Acorus)• Flowers: typical of Araceae, coalesced into a
spike-like spadix• Significant features: Sister to the rest of the
monocots; contain ethereal oils.• Special uses: none• Family not required, but Acorus
evolutionarily important
Acorus (sweet flag)– The most basal monocot! Aquatic.
“Petaloid” Monocots—Alismatales:Araceae
(The Arum Family)
• Cosmopolitan; greatest diversity in tropical regions• Mainly terrestrial and some aquatic herbs, vines,
epiphytes, floating aquatics• Diversity: 3,300 species, 104 genera• Flowers: many, small; lacking extensive perianth,
carpels 2-3; if unisexual then spatially separated in inflorescence or sometimes plants dioecious
• Significant features: inflorescence – spadix subtended by a spathe (specialized leaf)
• Special uses: many ornamentals; Colocasia as food• Required family
Araceae—Arisaema
Arisaema triphyllumJack-in-the-pulpit
Arisaema dracontiumgreen dragon
-Jack-in-the-pulpit is one of our common spring wildflowers
Arisaemasikokianum
Araceae
Monstera
Philodendron
Amorphophallus (Corpse flower)
http://www.youtube.com/watch?v=FHaWu2rcP94
Araceae: Lemna and friends
Lemna ~ duckweed
• Reduced plant body: no stem or leaves; sometimes no roots• Rarely flower
Alismatales: Araceae
Economic plants and products:
Colocasia esculenta• Taro “root” or dasheen“poi”
• 10% of the world uses as staple (starch) in diet
“Petaloid” Monocots—Alismatales:Alismataceae
(The Water Plantain Family)
• Widely distributed• Aquatic & wetland rhizomatous herbs• Number of species: 88 species, 15 genera• Flowers: sepals & petals distinct, many
apocarpous carpels; flowers or floral axes often whorled
• Significant features: rhizomatous• Special uses: ornamental aquatics• Family not required
Phylogeny of Monocot GroupsAcoralesAlismatalesLilialesAsparagalesDioscorealesPandanalesArecalesPoalesCommelinalesZingiberales
Basal“Petaloid”Commelinid
Liliales
• Nectaries at base of tepals
• Spots on tepals
• Extrorse anthers
“Petaloid” Monocots—Liliales:Liliaceae
(The Lily Family)• Widely distributed in temperate regions of
the Northern Hemisphere• Perennial herbs, usually with bulbs and
contractile roots• Number of species: ca. 600 species, in 16
genera• Flowers: tepals 6, distinct, carpels 3,
stamens 6 • Significant features: Fruit a loculicidal
capsule, sometimes a berry; no onion-like odor
• Special uses: many ornamentals• Required family
Liliaceae - Lilium
Liliaceae
Erythroniumtrout-lily
-native springwildflower of woodlands
Tulipa-scapose herbs from tunicate bulbs-leaves 2-several on a stem-perianth campanulate to cuplike -tepals 6, erect-stigma prominently 3-lobed
LiliaceaeEconomic plants and products (horticultural):
LiliumEaster lily
Tulipatulip
Phylogeny of Monocot GroupsAcoralesAlismatalesLilialesAsparagalesDioscorealesPandanalesArecalesPoalesCommelinalesZingiberales
Basal“Petaloid”Commelinid
Asparagales vs. Liliales
• Herbs; not succulent• Tepals often spotted• Nectaries at base of tepals/filaments• Styles 1 (trifid) or 3• Seed coat present• No phytomelan crust (seeds not black)
• Herbs to woody; sometimes succulent• Tepals not spotted• Nectaries septal• Style usually 1, simple• Seed coat collapsed to + present• Phytomelan crust (seeds black) from dry fruits; not in fleshy fruit
Figure 7.32 from the text
“Petaloid” Monocots—Asparagales: Alliaceae(Onion Family)
• Widely distributed in temperate and tropical regions; also semiarid.
• Bulb-forming herbs with basal, usually narrow leaves
• Number of species: ca. 600 species, in 13 genera• Flowers: Often showy, tepals 6, stamens 6, 3
connate carpels, ovary superior; inflorescence umbellate; fruit a loculicidal capsule.
• Significant features: sulfur-containing compounds (onion odor)
• Special uses: onion, garlic, leek, shallots, chives, used as food & seasonings; ornamentals
• Required family
Alliaceae - Allium
AlliaceaeEconomic plants and products:
• Allium species – onions, leeks, garlic!
Ornamentals
“Petaloid” Monocots—Asparagales: Iridaceae(The Iris Family)
• Widespread in tropical and subtropical regions; absent in Australia.
• Perennial herbs forming rhizomes, corms, or bulbs• Number of species: ca. 1,750 species, 67 genera• Flowers: radial or bilateral, showy; tepals 6, outer
tepals often differentiated from inner; stamens (2) 3, opposite outer tepals; carpels 3, fused into an inferior ovary; fruit a loculicidal capsule
• Significant features: leaves unifacial or terete, equitant
• Special uses: many ornamentals; saffron (Crocus sativus)
• Required family
Stamen positionopposite outertepals
Equitantleaves
Perennatingstructures
Iridaceae characters
Iridaceae diversity
Iris (Greek for rainbow)
-style branches broad, petaloid, terminating in paired crests -anthers appressed to style branches
Iris in wetland habitats
“Petaloid” Monocots—Asparagales:
Orchidaceae(The Orchid Family)• Widespread throughout the world; maximal diversity in
tropical regions• Primarily epiphytes; some terrestrial herbs, occasionally vines• Diversity: ca. 20,000 species in 700-800 genera• Flowers: showy, usually resupinate, bilateral, the median inner
tepal differentiated into a labellum (lip); highly modified androecial and gynoecial parts, fused into a column; pollen grouped into soft or hard masses (pollinia) united by a stalk into a pollinarium; ovary inferior; placentation parietal; fruit a capsule dehiscing with (1-)3 or 6 slits; seeds tiny, dust-like
• Significant features: among the most specialized of all angiosperm flowers
• Special uses: many ornamentals; Vanilla• Required family
Terrestrial
Orchid growth habits
Epiphytic
velamenOrchid roots
Orchid flower morphology
see Digital Flowers
Orchidaceae
Pollination• function of
column & pollinia
pollinarium
http://www.youtube.com/watch?v=wmgKABRCZpo&feature=related
Richard Dawkins talking about orchid pollination
Comet Orchid(Angraecum sesquipedale)
Morgan’s Sphinx Moth
Endemic toMadagascar
http://www.youtube.com/watch?v=OMVN1EWxfAU
Asparagales: Orchidaceae
Economic plants and products:
Vanilla flavoring extracted from immature capsules
of Vanilla planifolia
Some other cool Asparagales
Agavaceae
Amaryllidaceae
Agavaceae – Agave and Yucca
Agave
YuccaHosta
Agave: bat pollinated Yucca: moth pollinated
Asparagales: Agavaceae
Economic plants and products:
Agave tequila
Asparagales: AgavaceaeEconomic plants and products:
• Fiber for rope from species of Yucca and Agavee.g., sisal hemp
Amaryllidaceae diversity
Amaryllidaceae
Hymenocallisspider-lily
Narcissusdaffodil, jonquil, narcissus
Corona sometimes present