The Monocots: Part 2 Commelinid Monocots

1. The Monocots: Part 2Commelinid Monocots Spring 2013

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

3. Fig. 7.17

4. 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

5. Fig. 7.45

6. 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

7. 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

8. Arecaceae – Cocos nucifera

9. Arecaceae Economic plants and products: Cocos nucifera Coconut, oil

10. Arecaceae Economic plants and products: Phoenix dactylifera Dates

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

12. 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

13. Fig. 7.55

14. Zingiberalesdiversity

15. Fig. 7.56

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

17. 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

18. Fig. 7.63

19. 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

20. 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.

21. 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

22. Juncaceae Juncus Distichia

23. Juncaceae: Juncus -important in many wetland habitats

24. 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

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

26. Fig. 7.66D Fig. 7.65

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

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

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

30. 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

31. Cyperaceae: Carex

32. 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

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

34. Ecological importance

35. Poaceae: vegetative structure ligule

36. Poaceae: spikelet and flower structure flower Images from Grasses of Iowa

37. 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.

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

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

40. 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)

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

42. Dispersal!

43. Poaceae: Bamboos

44. Oryza (rice)

45. Triticum (wheat)

46. Zea (maize or corn)

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

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

49. “Graminoids” - Comparison

50. Next time: The “Basal” Eudicots…