in botany, a genus of the triandria digynia class. The calyx consists of three valves, the inmost of which is least. There are 28 species, four of which are natives of Britain, viz.: the viride, or green panic-grass; the crassifolii, or loose panic-grass; the sanguinale, or cock's-foot panic-grass; and the dactylon, or creeping panic grass.