The Collaborative International Dictionary
madagascar periwinkle \madagascar periwinkle\ n. (Bot.) A commonly cultivated Old World woody herb ( Vinca rosea) having large pinkish to red flowers.
Syn: periwinkle, rose periwinkle, Madagascar periwinkle, old maid, Cape periwinkle, red periwinkle, cayenne jasmine, Catharanthus roseus, Vinca rosea.
Wikipedia
Catharanthus roseus, commonly known as the Madagascar periwinkle or rosy periwinkle, is a species of flowering plant in the dogbane family Apocynaceae. It is native and endemic to Madagascar, but grown elsewhere as an ornamental and medicinal plant, a source of the drugs vincristine and vinblastine, used to treat cancer. Other English names include Vinca, Cape periwinkle, rose periwinkle, rosy periwinkle, and "old-maid". It was formerly included in the genus Vinca as Vinca rosea.