genus of the dogbane family (Apocynaceae), containing about 15 species of climbing plants native to Southeast Asia and Madagascar. Some botanists consider this genus a synonym of Marsdenia. Its members are hairless vines or shrubs that have opposite, undivided, leathery leaves. Their short-stalked flowers grow in clusters from the leaf axils and have a leafy, five-parted calyx and a tubular, five-lobed corolla that is swollen at its base. The best-known member of the genus, the Madagascar jasmine (Marsdenia floribunda), waxflower, or floradora, is a popular greenhouse plant. This woody, twining vine is native to Madagascar. It has leathery, oval leaves that grow up to 10 cm (4 inches) long and clusters of waxy, white flowers that grow to 5 cm and are exceedingly fragrant. Madagascar jasmine is grown out of doors in tropical or subtropical climates but is otherwise suitable only for tropical greenhouses.