in botany, a genus of the didynamia angiosperma clas. The calyx consists of five segments; the capsule is sharp-pointed, oblique, and has two cells; and the seeds are covered with a tunic. There are 14 species, two of which are natives of Britain, viz. the fylvatica, or common louse-wort; and the palustris, or marsh louse-wort.

This plant is of a cooling and drying nature, whence it is recommended in fistulas and other sinous ulcers.