SKULL-CAP, in botany: A genus of the gynopterigia order, belonging to the didynamia class of plants; and in the natural method ranking under the 40th order, Perforate. The calyx is short, tubulated, has the mouth entire, and cloe after flowering. There are two species in Britain, the galericulata and minor. 1. The Galericulata, Blue Skull-cap, or Hooded Willow-herb. The stems are weak, branched, and above a foot high; the leaves are heart-shaped, narrow-pointed, on short foot-stalks, and scalloped; the flowers are blue, in pairs, on pedicles from the axle of the leaves, and pendulous. It grows on the banks of rivers and lakes, is bitter, and has a garlick smell. 2. Minor, little red Skull-cap, or Willow-herb. The stalks are about eight inches high; the leaves are heart-shaped, oval; the flowers are purple. It grows in fens, and on the sides of lakes.