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The Monocots: Part 1 Overview, Basal, and “Petaloid” Groups. Spring 2012. 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 2012
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 cell plastids with several cuneate protein crystals • Lots of molecular support for monophyly
Additional features of monocots • Leaves formed from the basal end of the leaf primordium • Usually with monosulcate pollen • Lack glandular teeth on leaves
Monocot characters • One cotyledon! MONOCOT NON- MONOCOT
Monocot characters Leaves: • parallel venation in most monocots [may be reversals with net-venation!] • sheathing base Trillium Smilax
Monocot characters Cuneate protein bodies in sieve cell plastids • “wedge-shaped” inclusions • function unknown
Monocot characters Adventitious roots: -derived from structures other than another root
Monocot characters Scattered vascular bundles in stem • numerous; actually complex organization • no vascular cambium (a few weird exceptions)
Monocot characters • Pentacyclic, trimerous flowers with 2 perianth whorls and two whorls of stamens
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 (10,000 spp.)
Phylogeny of Monocot Groups Acorales Alismatales Liliales Asparagales Dioscoreales Pandanales Arecales Poales Commelinales Zingiberales Basal “Petaloid” Commelinoid
Basal and “Petaloid” Monocot Groups Order Acorales Acoraceae Order Alismatales Araceae Alismataceae Order Liliales Liliaceae Order Asparagales Agavaceae Alliaceae Amaryllidacaee Iridaceae Orchidaceae
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 • Terrestrial and aquatic herbs, vines, epiphytes, floating aquatics • Diversity: 3,300 species, 109 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 taxa: Arisaema, Lemna
Araceae—Arisaema Arisaema dracontium green dragon Arisaema triphyllum Jack-in-the-pulpit Arisaema sikokianum -spathe margins overlapping below, spathe mostly arched above, striped or marked -spadix usually slender and elongate -flowers unisexual and only at the base of the spadix
Araceae Philodendron Monstera
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” Commelinoid
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 taxa: Erythronium, Tulipa
Liliaceae Erythronium trout-lily -bulbs ovate to elongate -scapose herbs with 2 leaves (1 if non-flowering) -tepals 6, spreading to reflexed -native wildflowers
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” Commelinoid
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 taxa: Allium
-scapose herbs with bulbs + contractile roots -basally clustered leaves -umbellate inflorescence with bracts -6 petaloid tepals + 6 stamens -loculicidal capsule + black seeds Alliaceae - Allium
Alliaceae Economic plants and products: • Allium species – • onions, leeks, garlic! Ornamentals
“Petaloid” Monocots—Asparagales:Agavaceae(The Agave Family) • Warm temperate to tropical regions of the New World; maximum diversity in Mexico • Rosette herbs to small trees, often with succulent leaves • Number of species: ca. 300 species in 8-13 genera • Flowers: tepals 6, stamens 6, carpels 3, fruits a loculicidal capsule • Significant features: large, paniculate inflorescence; dimorphic chromosomes • Special uses: fiber, tequila, ornamentals. • Family not required
Agavaceae – Agave and Yucca Agave Yucca
Agave: bat pollinated Yucca: moth pollinated
Perianth tubular-funnelform, 6-parted Stamens exserted beyond the perianth, anthers versatile Ovary inferior Capsule loculicidal Bat-pollinated Perianth of 6 flat, free tepals Stamens shorter than the tepals, anthers basifixed Ovary superior Fruit indehiscent (berry-like) or septicidal capsule Moth-pollinated Agave (L) vs. Yucca (R)
Agavaceae: Hosta -rhizomatous, scapose perennials -leaves with a distinct petiole -perianth tubular-funnelform, white, bluish or lavender -stamens 6, epipetalous or hypogynous -fruit a loculicidal capsule
Asparagales: Agavaceae Economic plants and products: Agave tequila
Asparagales: Agavaceae Economic plants and products: • Fiber for rope from species of Yucca and Agave • e.g., sisal hemp
“Petaloid” Monocots—Asparagales: Amaryllidaceae(Amaryllis or Daffodil Family) • Widely distributed in temperate to tropical regions; maximal diversity in South Africa, Andean South America, and the Mediterranean • Bulb-forming herbs with contractile roots • Number of species: 850 species in 59 genera • Flowers: often showy; tepals 6; stamens 6, sometimes adnate to perianth; carpels 3, inferior ovary; fruit usually a loculicidal capsule • Significant features: special alkaloid compounds present • Special uses: many ornamentals (Narcissus, Hippeastrum) • Family not required
Amaryllidaceae Corona sometimes present Narcissus daffodil, jonquil, narcissus Hymenocallis spider-lily
Narcissus -scapose, perennial herbs from bulbs -perianth of 6 basally connate tepals, yellow and/or white -cuplike to trumpetlike corona present -stamens 6, epipetalous
Amaryllidaceae: Hippeastrum -perennial, scapose herbs from large bulbs -perianth of 6 basally connate tepals, white to pink to salmon or red -corona minute -stamens 6, epipetalous
“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 taxa: Iris