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.
Common Name: DOGBANE, INDIAN HEMP
Habit: Perennial herb, ascending or erect. Leaf: opposite. Inflorescence: generally cyme, >> 6-flowered. Flower: < 8 mm; corolla bell- or urn-shaped to cylindric, 5-lobed, with 5 triangular appendages alternate stamens; filaments free, attached at base of corolla tube, unappendaged, short, broad, anthers forming cone around and adherent to stigma, each partly sterile, sharply sagittate, pollen +- free; nectaries 5, free, around but not exceeding ovaries; ovaries free, not adherent, style +- 0, stigma massive, ovoid, obscurely 2-lobed. Fruit: slender, cylindric, pointed. Seed: with tuft of long hairs at 1 end.
Species In Genus: 7 species: North America. Etymology: (Greek: away from, dog, from ancient use as dog poison) Note: 2 geographically overlapped but ecologically different species in California, many hybrids between them, many of these named.
Unabridged Note: 2 geographically overlapped but ecologically different species in California, many hybrids between them. Of many names proposed for these, some (e.g., Apocynum androsaemifolium var. glabrum Macoun; Apocynum medium Greene var. floribundum (Greene) Woodson; Apocynum pumilum (Gray) Greene; Apocynum pumilum var. rhomboideum (Greene) Beg. & Bel.) applied to plants more like Apocynum androsaemifolium, others (e.g., Apocynum cannabinum var. glaberrimum A. DC.; Apocynum sibiricum Jacq. var. salignum (Greene) Fern.) to plants more like Apocynum cannabinum; none here accepted since extent of such subdivision +- limitless.
eFlora Treatment Author: Thomas J. Rosatti & Lauramay T. Dempster