Apocynum was the name given to one of the species by Dioscorides because it was supposedly poisonous to dogs, Greek apo away and kyon dog. Herbs, vines, shrubs and trees. This family now incorporates the family Asclepiadaceae. Leaves opposite or whorled, rarely alternate, simple, entire, gland-like colleters are frequently present either at the junction of petiole and lamina or along the interpetiolar rim. Latex present, usually white. Flowers regular, 5-merous, corolla-lobes usually overlap in bud. Stamens united around the style, may form a special structure with the stigma. Ovary of 2 carpels, rarely fully fused at the base; fruit usually 1-2 follicles, maybe fleshy.