ASCLEPIAS, in botany, a genus of the pentandria digynia class. The generic character is taken from five oval, concave, horn-like nectaria, which are found in the flower. There are 18 species of asclepias, none of which grow wild in Britain. The root is used by the French and German physicians as a sudorific, diuretic, and emmenagogue; but it is not in use with us.