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The Monocots: Part 1 Overview, 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
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The Monocots: Part 1Overview, Basal, and “Petaloid” Groups Spring 2014
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 characters Adventitious roots: -derived from structures other than another root
Monocot characters • One cotyledon! MONOCOT NON- MONOCOT
Monocot characters Scattered vascular bundles in stem • numerous; actually complex organization • no vascular cambium (a few weird exceptions)
Monocot characters Leaves: • 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 characters Cuneate 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.)
Phylogeny of Monocot Groups Acorales Alismatales Liliales Asparagales Dioscoreales Pandanales Arecales Poales Commelinales Zingiberales Basal “Petaloid” Commelinid
Basal and “Petaloid” Monocot Groups Order Acorales Acoraceae Order Alismatales Araceae* Alismataceae Order Liliales Liliaceae* Order Asparagales Agavaceae Alliaceae* Amaryllidaceae Iridaceae* 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 dracontium green dragon Arisaema triphyllum Jack-in-the-pulpit Arisaema sikokianum -Jack-in-the-pulpit is one of our common spring wildflowers
Araceae Philodendron Monstera
Amorphophallus(Corpse flower) http://www.youtube.com/watch?v=FHaWu2rcP94
Araceae: Lemna and friends • Reduced plant body: no stem or leaves; • sometimes no roots • Rarely flower Lemna ~ duckweed
Alismatales: Araceae Economic plants and products: • Colocasia esculenta • Taro “root” or dasheen • “poi” • 10% of the world uses asstaple (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 Groups Acorales Alismatales Liliales Asparagales Dioscoreales Pandanales Arecales Poales Commelinales Zingiberales 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 Erythronium trout-lily -native spring wildflower 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
Liliaceae Economic plants and products (horticultural): Tulipa tulip Lilium Easter lily
Phylogeny of Monocot Groups Acorales Alismatales Liliales Asparagales Dioscoreales Pandanales Arecales Poales Commelinales Zingiberales Basal “Petaloid” Commelinid
Asparagales vs. Liliales • 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 • 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)
“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 Economic 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
Perennating structures Equitant leaves Stamen position opposite outer tepals Iridaceae characters
Iris (Greek for rainbow) -style branches broad, petaloid, terminating in paired crests -anthers appressed to style branches
“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
Orchid growth habits Epiphytic Terrestrial
Orchid roots velamen
Orchid flower morphology see Digital Flowers
Orchidaceae pollinarium • Pollination • function of column & pollinia
http://www.youtube.com/watch?v=wmgKABRCZpo&feature=related Richard Dawkins talking about orchid pollination
Comet Orchid (Angraecum sesquipedale)
http://www.youtube.com/watch?v=OMVN1EWxfAU Morgan’s Sphinx Moth Endemic to Madagascar
Asparagales: Orchidaceae Economic plants and products: Vanilla flavoring extracted from immature capsules of Vanilla planifolia