Cochliasanthus

Cochliasanthus caracalla is a leguminous flowering plant in the family Fabaceae that originates in tropical South America and Central America. The species is named caracalla, a corruption of the Portuguese caracol, meaning snail.

This perennial vine (when grown in a climate without frost) has fragrant flowers said to be reminiscent of hyacinths - with a distinctive curled shape, giving rise to the common names corkscrew vine, snail vine, snail creeper, snailflower or snail bean. It is the only member of the genus Cochliasanthus and was formerly considered to belong to the genus Vigna.

Two very different plant species are sold and cultivated under this one name. One plant is the true Cochliasanthus caracalla. The other, also called "Phaseolus giganteus" (a horticultural name, not validly published), appears to be Vigna speciosa or a close relative. Thomas Jefferson called this plant "the most beautiful bean in the world".