Diversity And Classification of Flowering Plants: Eudicots: Asterids Michael G. Simpson

1. Diversity And Classification of Flowering Plants: Eudicots: AsteridsMichael G. Simpson

5. Asterids • Very large, diverse group • 10 orders, many families • Putative apomorphies: • iridoid compounds • sympetalous corolla • ovules: unitegmic (one integument), tenuinucellate (megasporangium 1-cell thick)

6. Ovules unitegmic, tenuinucellate

12. Apiaceae(=Umbelliferae) -Carrot family(Apium, used in Pliny for a celery-like plant). 446 genera / 3,540 spp. The Apiaceae are distinctive in being herbs, with sheathingleaves, (compound or simple. often decompound), the inflorescence usually an involucratecompound umbel [rarely a head, simple umbel, or reduced] with actinomorphic flowers having a 2-carpellate and 2-loculate, inferiorovary, each carpel with one, axile-apical, pendulous ovule, the fruit a schizocarp of mericarps. K 5 or 0 C 5 [0] A 5 G (2), inferior, hypanthium absent.

13. Economically important members include a number of food, herb, and spice plants, such as Anethum, dill; Apium, celery; Carum, caraway; Coriandrum, coriander; Cuminum, cumin; Daucus, carrot; Foeniculum, fennel; and Petroselinum, parsely; some species are poisonous, such as Conium maculatum, poison-hemlock; others are used as ornamental cultivars.

14. Leavessheathing

15. Inflorescence an umbel, compound umbel, or head

16. ovary inferior placentation apical-axile stylopodium

17. Fruit a schizocarp of mericarps

18. Araliaceae- Ginseng family (possibly from French Canadian Aralie). 47 genera / 1,325 species. The Araliaceae are distinctive in being mostly tropical trees, shrubs, lianas, or herbs with palmate or pinnate (rarely simple, then usually divided) leaves, an inflorescence of heads, umbels, or with umbel units, the flowers with often reduced calyx, apopetalous to sympetalous corolla, and a 1-∞-carpellate inferior ovary with usually apical-axile placentation, the fruit a berry, drupe, or schizocarp. K 0-5 C 5 [3-12] A 5-10 [3-∞] G (2-5) [(-∞)], inferior, rarely superior.

23. Asteraceae (Compositae) Characteristics: Vegetatively variable. Inflorescence a head (capitulum): (usu.) many flowers arising from a compound receptacle, subtended by inflorescence bracts: involucral bracts or phyllaries, collectively termed the involucre. Calyx modified as pappus. Stamens syngenesious. K pappus C 5 A (5) G(2), inferior, 1 basal ovule Fruit an achene.

24. Asteraceae(=Compositae) - Sunflower family (after Aster, meaning star). 1,528 genera / 22,750 species. The Asteraceae are distinctive in being herbs, shrubs, vines, or trees, the inflorescence a head (capitulum) subtended by an involucreof phyllaries, flowers either bilabiate, disk, or ray/ligulate, (heads of many taxa a mixture of central disk flowers and peripheral ray flowers), with the calyx, termed a pappus, modified as scales, awns, or capillary bristles (or absent), the androecium syngenesious, and with an inferior ovary with a single, basal ovule, the fruit a multiple of achenes.

25. Asteraceae(=Compositae) - Sunflower family (after Aster, meaning star). 1,528 genera / 22,750 species. Economic importance includes some food plants (e.g., Cynara scolymus, artichoke, and Helianthus annuus, sunflower), a number of ornamental cultivars, and various species used locally or industrially; the prickly fruits of Arctium lappa (burdock) are purported to have been the model for invention of velcro.

26. Argyroxiphium sandwicense, SilverswordMaui

27. Argyroxiphium sandwicense, SilverswordMaui

28. Asteraceae(=Compositae) - Sunflower family (after Aster, meaning star). 1,528 genera / 22,750 species. K 0-∞ (pappus) C (5) [(4)] or (3) in some ray flowers A (5) [(4)] G (2), inferior, hypanthium absent.

29. Asteraceae: floral variation Three types of flowers: 1) Bilabiate: zygomorphic (bilateral) with 2 lips 2) Ray (ligulate): zygomorphic (bilateral) with 1 lobe 3) Disk: actinomorphic (radial), usu. 5-lobed

30. Five types of heads: 1) discoid, with only disk flowers; 2) disciform, with central disk flowers and marginal, eligulate female flowers; 3) radiate, with central (bisexual or male) disk flowers and peripheral (female or sterile) ray flowers; 4) ligulate, with all ray flowers (typically with 5-toothed corolla apices); 5) bilabiate, with all bilabiate flowers.

31. Bilabiate flower posterior lip anterior lip Acourtia microcephala Trixis californica

34. Ray flowers (heads ligulate = all rays) ligulate corolla Rafinesquia neomexicana Malacothrix californica

35. Disk flower: heads discoid disk corolla Palafoxia arida Chaenactis gabriuscula Psathyrotes ramosissima

36. Disk flowers: heads disciform(2 types of disk fls., same or different heads) male heads female heads Ambrosia chamissonis

37. Heads radiate: inner disk & outer ray fls. disk flowers ray flowers Xylorhiza orcuttii Encelia farinosa

38. Some heads are "chaffy" ovary disk flower Encelia californica chaff : bracts subtending flowers

39. Involucre morphology two whorls many whorls one whorl Senecio vulgaris Coreopsis maritima Encelia californica

40. Involucre morphology Phyllaries spiny & squarrose Phyllaries spiny Circium vulgare Silybum marianum

41. Pappus: modified calyx beak capillary bristles, borne atop "beak" capillary bristles: barbellate capillary bristles: plumose

42. Pappus: modified calyx