in botany, a genus of the pentandria monogyne clas. The calix is rotated; and the capsule is roundish, with a sharp point, and contains ten valves. There are eleven species, five of them natives of Britain, viz. the vulgaris, or yellow willow herb; the triflora, or tufted loofe-strife; the nemorium, or yellow pimpernell of the woods; the nummularia, or money wort; and the tenella, or purple money-wort.