The Monocots: Part 1 Overview, Basal, and “Petaloid” Groups Spring 2011

Figure 9.1 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 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 Asparagales Liliales 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: 2,830 species, 109 genera Flowers: many, small; lacking extensive perianth, carpels 2-3; 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 triphyllum Jack-in-the-pulpit Arisaema dracontium green dragon -spathe overlapping below, mostly arched above, striped or marked -spadix usually slender and elongate -flowers unisexual and only at the base of the spadix Arisaema sikokianum

Araceae Monstera Philodendron

Amorphophallus

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: 80 species, 11 genera Flowers: sepals & petals distinct, many apocarpous carpels Significant features: rhizomatous Special uses: ornamental aquatics Required taxa: Sagittaria

Liliales: Liliaceae in the broad sense …are a garbage can taxon.

Plus many members of Asparagales… Figure 9.14 from the text

“Petaloid” Monocots—Liliales: Liliaceae (The Lily Family) Widely distributed in temperate regions of the Northern Hemisphere Herbs, usually with bulbs or 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 Special uses: many ornamentals Required taxa: Erythronium, Tulipa

Liliaceae - Lilium

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): Lilium Easter lily Tulipa tulip

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 9.18 from the text

“Petaloid” Monocots—Asparagales: Agavaceae (The Agave Family) Warm temperate to tropical regions of the New World; maximum diversity in Mexico Rosette herbs, 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 Special uses: fiber, tequila, ornamentals. Required taxa: Agave, Yucca, Hosta

Agavaceae – Agave and Yucca Agave Yucca

Agave: bat pollinated Yucca: moth pollinated

Agave (L) vs. Yucca (R) 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

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: Alliaceae (Onion Family) Widely distributed in temperate and tropical regions; also semiarid. Bulb-forming herbs Number of species: ca. 645 species, in 13 genera Flowers: Often showy, tepals 6, stamens 6, 3 connate carpels, ovary superior; fruit a loculicidal capsule. Significant features: sulfur-containing compounds Special uses: onion, garlic, leek, shallots, chives, used as food & seasonings; ornamentals Required taxa: Allium

Alliaceae - Allium -scapose herbs with bulbs + contractile roots -basally clustered leaves -umbellate inflorescence with bracts -6 petaloid tepals + 6 stamens -loculicidal capsule + black seeds

Alliaceae Economic plants and products: Allium species – onions, leeks, garlic! Ornamentals

“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: 870 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) Required taxa: Narcissus, Hippeastrum

Amaryllidaceae diversity

Amaryllidaceae Hymenocallis spider-lily Narcissus daffodil, jonquil, narcissus Corona sometimes present

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. 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; carpels 3, fused into an inferior ovary; fruit a loculicidal capsule Significant features: leaves equitant Special uses: many ornamentals; saffron (Crocus sativus) Required taxa: Iris

Iridaceae diversity

Iris -rhizomatous herbs -leaves equitant, in a fan -spathes 2 -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. 19,500 species in 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); 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 taxa: family only

Orchid flower morphology

Orchidaceae Pollination function of column & pollinia

Richard Dawkins talking about orchid pollination

Asparagales: Orchidaceae Economic plants and products: Vanilla flavoring extracted from immature capsules of Vanilla planifolia