Stephanotis, genus of the dogbane family (Apocynaceae), containing about 15 species. 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 flowers present as narrow, tubular, waxy horns about 2 inches (5 cm.) in length and are exceedingly fragrant. It blooms in Spring, Summer.