Common Name: DOGBANE FAMILY
Habit: Annual, perennial herb, shrub, tree, often vine; sap generally milky. Leaf: simple, alternate, opposite, subwhorled to whorled, entire; stipules 0 or small, finger-like. Inflorescence: axillary or terminal, cyme, generally umbel- or raceme-like, or flowers 1--2. Flower: bisexual, radial; perianth parts, especially petals, overlapped, twisted to right or left, at least in bud; sepals generally 5, fused at base, often reflexed, persistent; petals generally 5, fused in basal +- 1/2; stamens generally 5, attached to corolla tube or throat, alternate lobes, free or fused to form filament column and anther head, filament column then generally with 5 free or fused, +- elaborate appendages abaxially, pollen +- free or removed in pairs of pollinia; nectaries 0 or near ovaries, then 2 or 5, or in stigmatic chambers; ovaries 2, superior or +- so, free [fused]; style tips, stigmas generally fused into massive pistil head. Fruit: 1--2 follicles, (capsule), [berry, drupe]. Seed: many, often with tuft of hairs at 1 or both ends.
Genera In Family: 200--450 genera, 3000--5000 species: all continents, especially tropics, subtropical South America, southern Africa; many ornamental (including Asclepias, Hoya, Nerium, Plumeria, Stapelia); cardiac glycosides, produced by some members formerly treated in Asclepiadaceae, used as arrow poisons, in medicine to control heart function, and by various insects for defense. Note: Asclepiadaceae ("asclepiads"), although monophyletic, included in Apocynaceae because otherwise the latter is paraphyletic. Complexity of floral structure, variation in asclepiads arguably greatest among all angiosperms. Pattern of carpel fusion (carpels free in ovule-bearing region, fused above), present +- throughout Apocynaceae (in broad sense), nearly unknown in other angiosperms. Base chromosome number generally 11; abundance of latex, generally small size of chromosomes evidently have impeded cytological investigations.
eFlora Treatment Author: Thomas J. Rosatti, except as noted
Scientific Editor: Bruce G. Baldwin.
Habit: Perennial herb [shrub]. Stem: twining [prostrate to erect]. Leaf: opposite; blade ovate, cordate, hastate [round]. Inflorescence: at nodes, flowers 1--2peduncles < pedicels or 0 [raceme-, umbel-, or panicle-like cyme]. Flower: corolla spreading to +- erect, ring of tissue at base 0; filament column appendages fused into 5-lobed, cup- or plate-like structure around anther head [free], attached to base of filament column, each with a vertical, flap-like projection fused to filament column, forming compartments within cup [projections otherwise or 0], solid (margins fused to those of adjacent filament column appendages), anthers fused into anther head around and fused to pistil head, pollen in pollinia; pistil head flat; nectaries in stigmatic chambers. Fruit: erect or pendent, fusiform to lance-ovoid or ovoid, smooth, with tubercles [longitudinal wings]. Chromosomes: 2n=22 (reports not including California plants).
Species In Genus: In broad sense of genus, 200 species: tropics, warm temperate America.