Gomphocarpus R.Br.
Erect perennial herbs or small shrubs, with milky latex. Lvs opposite or verticillate, sometimes the uppermost alternate, simple. Fls in axillary cymes; cymes umbellate. Calyx small, deeply lobed, glandular inside. Corolla valvate in bud, rotate, deeply 5-lobed; segments becoming reflexed at anthesis. Corona of 5 erect or spreading scales, hood-like, sometimes curved over the anthers, with 2 lateral teeth. Stamens inserted near base of corolla; anthers with an incurved apical membrane; pollinium solitary and pendulous in each cell, attached to a gland on the stigma. Carpels free; stigma 5-angled. Follicles smooth, bristly or softly spinose, inflated.
c. 50 spp., tropical and subtropical Africa. Naturalised sp. 1.
Authorities disagree as to whether this genus should be included within the large, mainly American genus Asclepias L.. The main character used to separate them is the presence of a ligular horn-like appendage on the corona in Asclepias. The tropical American A. curassavica L. is fairly commonly cultivated in warmer parts of the North Id. This is more or less herbaceous and has red or purplish corolla lobes and orange corona scales. It is commonly naturalised in the tropical and subtropical Pacific.