Secamonoideae-Milkweed and stapeliad family

 Description of the family:
Perennial herbs or shrubs, sometimes twining or scrambling, often succulent and often with milky sap. Stipules usually 0. Leaves mainly opposite or whorled, rarely alternate, simple and usually entire. Flowers in umbels or cymes or, rarely, in racemes, actinomorphic, bisexual. Calyx usually of 5 free sepals, sometimes 5-lobed. Corolla gamopetalous, very variable; lobes 5, sometimes connate at tips. Corona usually arising from or near base of the staminal column, in 1-3 series, consisting of 5 free or connate lobes or processes, rarely 0. Filaments united into a staminal column, often short; anthers with horny wings; pollen in waxy masses attached by caudicles to a horny carrier. Ovaries 2, superior, each 1-locular. Fruit of 2 follicles, sometimes only one developing. Seeds usually with marginal wing and a tuft of long, silky hairs at apex. A difficult family because it lacks a consistent and complete modern coverage. Extensive use has been made of the keys and descriptions in Leistner (2000) and Leistner (2005).