Operculina Silva Manso is a genus of approximately 15–30 species of twining, herbaceous to semi-woody vines belonging to the morning-glory family, Convolvulaceae (order Solanales). The genus was established by E.F.L. Silva Manso in 1836. Operculina is distributed across the pantropics — from South and Southeast Asia and the Pacific Islands through tropical Australia, sub-Saharan Africa, and the Americas.
Members of Operculina are perennial or annual climbers with characteristically winged or angled stems. Leaves are alternate, simple, and often ovate to heart-shaped at the base. Flowers are funnel- or bell-shaped (campanulate), white or whitish, and closely resemble those of related morning-glory genera such as Ipomoea. The most distinctive feature of the genus is its fruit: a globose capsule that dehisces in an operculate fashion — the top of the capsule separates like a lid, a trait reflected in the genus name (Latin operculum, lid).
The best-known species is Operculina turpethum (turpeth, Indian jalap), a robust vine widely distributed from India and East Africa to Papua New Guinea and northern Australia, and long used in Ayurvedic medicine. Operculina macrocarpa, native to the Caribbean and tropical Americas, and Operculina hamiltonii are among other recognised species. The genus shows its greatest diversity in the Indo-Pacific region.
Etymology
The name Operculina derives from the Latin operculum, meaning "lid" or "cover," and refers to the distinctive operculate dehiscence of the seed capsule, in which the top of the fruit separates like a lid when ripe. The genus was described by the Brazilian botanist E.F.L. Silva Manso in his 1836 work Enumeração das Substâncias Brazileiras.
Distribution
Operculina has a pantropical distribution spanning South and Southeast Asia, the Pacific Islands, Australia (Queensland, Northern Territory, and Western Australia), sub-Saharan Africa, Madagascar, the Indian Ocean islands, and the tropical Americas from Brazil and Bolivia north through Central America, the Caribbean, Mexico, and as far as Texas. The genus reaches its greatest species diversity in the Indo-Pacific region.
Cultural Uses
Operculina turpethum, known as turpeth or Indian jalap (and in Ayurveda as Trivrit), has a long history of medicinal use in South and Southeast Asia as a purgative. It is documented in classical Ayurvedic texts and referenced in the Ayurvedic reference Ayurveda: The Divine Science of Life (Caldecott, 2006). The species is also known by local common names including fue vao and St. Thomas lidpod.
