The Monocots: Part 2 Commelinid Monocots Spring 2013

Phylogeny of Monocot Groups Acorales Alismatales Asparagales Liliales Dioscoreales Pandanales Arecales Poales Commelinales Zingiberales Basal “Petaloid” Commelinid

Fig. 7.17

Commelinid characters Special type of epicuticular wax Starchy pollen UV-fluorescent compounds in the cell walls Starchy endosperm (except in the palms) Lots of molecular support

Fig. 7.45

Commelinid Monocot Groups Order Arecales – Palms Arecaceae (Palmae) Order Commelinales – Spiderworts, bloodworts, pickerel weeds Order Zingiberales – Ginger, banana, and allies Order Poales – Bromeliads, Cat-tails, Rushes, Sedges, and Grasses Typhaceae* Juncaceae* Cyperaceae* Poaceae (Gramineae)* *required families

Commelinoid Monocots: Arecales: Arecaeae (Palmae) Widespread throughout tropical and warm temperate regions “Trees” or “shrubs”, typically unbranched Diversity: ca. 2,000 species in 190 genera Flowers: usually sessile, in compound-spicate inflorescences, these subtended by a bract (spathe); ovule 1 per locule Significant features: Leaves alternate or spiral, blades plicate, splitting in a pinnate or palmate manner Special uses: coconut (Cocos nucifera), date (Phoenix dactylifera), rattan (Calamus), oils and waxes, ornamentals Family not required

Arecaceae – Cocos nucifera

Arecaceae Economic plants and products: Cocos nucifera Coconut, oil

Arecaceae Economic plants and products: Phoenix dactylifera Dates

Phylogeny of Monocot Groups Acorales Alismatales Asparagales Liliales Dioscoreales Pandanales Arecales Poales Commelinales Zingiberales Basal “Petaloid” Commelinid

Commelinid Monocots: Zingiberales Large herbs with vessels more or less limited to the roots Silica cells present in the bundle sheaths Leaves clearly differentiated into a petiole and blade Leaf blade with penni-parallel venation, often tearing between the second-order veins Leaf blade rolled into a tube in bud Petiole with enlarged air canals Flowers bilateral (or irregular) Pollen lacking an exine Ovary inferior Seeds arillate and with perisperm (diploid nutritive tissue derived from the nucellus) 8 families and nearly 2000 species, mainly tropical Not required

Fig. 7.55

Zingiberales diversity

Fig. 7.56

Phylogeny of Monocot Groups Acorales Alismatales Asparagales Liliales Dioscoreales Pandanales Arecales Poales Commelinales Zingiberales Basal “Petaloid” Commelinid

Characters of Poales Silica bodies (in silica cells) in the epidermis Styles strongly branched Loss of raphide (needle-like) crystals in most Much molecular support for monophyly Wind pollination has evolved several times independently within the order Ecologically extremely important

Fig. 7.63

Commelinoid Monocots—Poales: Typhaceae (The Cattail Family) Widely distributed, especially in Northern Hemisphere Emergent aquatic rhizomatous herbs Diversity: 8-13 species in 1 genus Flowers: small, unisexual; separated spatially on dense, compact spicate inflorescences; placentation apical Significant features: rhizomatous; long slender leaves; characteristic inflorescence Special uses: ornamental aquatics Required taxa: Typha

Sparganium Typha This genus is placed in its own family, the Sparganiaceae, in your text, but it is closely related to Typhaceae and is included in Typhaceae in many treatments.

Commelinid Monocots—Poales: Juncaceae (The Rush Family) Worldwide, mostly temperate regions; wet or damp habitats Rhizomatous herbs, stems round and solid Diversity: 350 species in 6 genera Flowers: tepals 6, distinct; carpels 3 in superior ovary; stamens 6; fruit a loculicidal capsule Significant features: leaves 3-ranked, sheaths usually open Special uses: leaves used to weave rush baskets; some ornamentals Required taxa: Juncus

Juncaceae Juncus Distichia

Juncaceae: Juncus -important in many wetland habitats

Commelinid Monocots—Poales: Cyperaceae (The Sedge Family) Worldwide, usually in damp or semi-aquatic sites Rhizomatous herbs, stems usually triangular in cross section and solid Diversity: 5,000 species in 104 genera Flowers: with 1 subtending bract; tepals absent or reduced to 3-6 scales or hairs; stamens 1-3; carpels 2-3 in superior ovary; fruit an achene (nutlet) Significant features: Inflorescence a complex group of spikelets; leaf sheaths closed, ligule lacking; silica bodies conical Special uses: Papyrus used originally for paper; “water chestnuts” and a few other rhizomes edible, leaves used for weaving; some ornamentals. Required taxa: Carex

Cyperaceae versus Juncaceae: Field Character “Sedges have edges… …and rushes roll.”

Fig. 7.66D Fig. 7.65

Cyperaceae Flowers: Arranged in spikelets Reduced Wind-pollinated Subtended by one bract Reduced/absent perianth flower + subtending bract = floret flower Sedge spikelet From Zomlefer 1994

Cyperaceae Fruit type is the achene: very important in the taxonomy of the family. Eleocharis Rhynchospora (note bristle perianth) Cyperus

Cyperaceae http://waynesword.palomar.edu/termfl3.htm

Cyperaceae: Carex -presence of the perigynium (a sac-like bract surrounding the female flower) in addition to the subtending bract -leaves usually with a ligule -ecologically important, especially in wetlands

Cyperaceae: Carex

Commelinid Monocots—Poales: Poaceae (Gramineae) (The Grass Family) Cosmopolitan Primarily herbs, often rhizomatous; “trees” in most bamboos; stems are called culms, hollow or solid Diversity: >11,000 species in ca. 650 genera Flowers: small petals reduced to lodicules; each flower enclosed by two bracts (lemma and palea) = floret; stamens typically 3; carpels 3, but appearing as 2; fruit a caryopsis Significant features: 1-many florets aggregated into spikelets, each with usually 2 empty bracts (glumes) at the base; leaf with a ligule Special uses: many – grains, turf, fodder/forage, structural uses (e.g., bamboo). Required family

Economic importance bamboo sugar cane Zea mays weeds Oryza sativa Triticum aestivum

Ecological importance

Poaceae: vegetative structure ligule

Poaceae: spikelet and flower structure Images from Grasses of Iowa

Anatomy of the Caryopsis (Grain) The fruit wall (pericarp) is completely fused to the seed coat. Endosperm (3N; triploid) contains the bulk of starch storage in the seed. The embryo is a pre-formed grass plant, with apical meristems (for both shoot and root) and protective organs (coleoptile and coleorhiza) which emerge first during germination.

Poaceae: caryopsis (grain) Zea mays corn or maize Setaria foxtail

Origin of grasses ca. 70-80 mya in southern- hemisphere forests early grasses Origin of grasses ca. 70-80 mya in southern- hemisphere forests

Origin of grasses ca. 70-80 mya in forests Anomochlooideae Pharoideae Puelioideae Bamboos (Bambusoideae) Origin of grasses ca. 70-80 mya in forests Bluegrasses (Pooideae) Rices (Ehrhartoideae) Panicgrasses (Panicoideae) Major radiation in Oligocene- Miocene epochs into open habitats Needlegrasses (Aristidoideae) Lovegrasses (Chloridoideae) + Micrairoideae Stamens reduced to 3 Reeds (Arundinoideae) Oatgrasses (Danthonioideae)

C4 photosynthetic pathway (in warm season grasses) is advantageous under higher temperatures, higher light, and less water

Dispersal!

Poaceae: Bamboos

Oryza (rice)

Triticum (wheat)

Zea (maize or corn)

For more information and images: http://www. eeob. iastate For more information and images: http://www.eeob.iastate.edu/research/iowagrasses/ The Grasses of Iowa

Grasses, Sedge, Rushes! Stem terete, hollow, or solid, jointed Leaf ranks 2 Leaf sheath Open, ligule Inflor: Spikelets Perianth: Lodicules Fruit: Caryopsis Triangular, solid, not obviously jointed 3 Closed Spikelets None or bristles/scales Achene Terete, solid, not obviously jointed 3 Open Cymose 6 chaffy tepals Capsule

“Graminoids” - Comparison

Next time: The “Basal” Eudicots…