Presentation on theme: "Diversity And Classification of Flowering Plants: Eudicots: Asterids Michael G. Simpson."— Presentation transcript:
Diversity And Classification of Flowering Plants: Eudicots: Asterids Michael G. Simpson
Asterids Very large, diverse group 10 orders, many families Putative apomorphies: –iridoid compounds –sympetalous corolla –ovules: unitegmic (one integument), tenuinucellate (megasporangium 1-cell thick)
Ovules unitegmic, tenuinucellate
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 sheathing leaves, (compound or simple. often decompound), the inflorescence usually an involucrate compound umbel [rarely a head, simple umbel, or reduced] with actinomorphic flowers having a 2-carpellate and 2-loculate, inferior ovary, each carpel with one, axile-apical, pendulous ovule, the fruit a schizocarp of mericarps. K 5 or 0 C 5  A 5 G (2), inferior, hypanthium absent.
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.
Inflorescence an umbel, compound umbel, or head
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.
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.
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 involucre of 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.
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.
Argyroxiphium sandwicense, Silversword Maui
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.
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
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.