PLANT: Trees, shrubs, vines, or perennial herbs, usually with milky sap. LEAVES: opposite, alternate, or whorled, simple, entire, estipulate. INFLORESCENCE: cymes to panicles, or flowers solitary. FLOWERS: perfect, actinomorphic; calyx lobes 5, imbricate in bud; corolla 5-merous, syrnpetalous, twisted in bud, campanulate to salverform; stamens 5, epipetalous, alternating with the lobes, the anthers often connivent around the stigma; pistil 2-carpelled, ovaries 2, superior, distinct or united apically, each l-loculed, the style 1 with a single, often enlarged stigma. FRUIT: (in ours) a pair of follicles, the seeds several, naked or comose. NOTES: 215 genera, 2100 spp., mostly tropical with a few temperate. Includes many important drug plants (Strophanthus, Catharanthus) and ornamentals (Nerium, Vinca, Thevetia). Woodson, R. E. 1938. N. Amer. Flora 29:103-192. Rosatti, T. J. 1989. J. Arnold Arbor. 70:307-401. REFERENCES: McLaughlin, Steven, P. 1994. Apocynaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 164-168.