Any of about 500 species of herbaceous plants that make up the genus Pedicularis in the snapdragon family. The lousewort is found throughout the Northern Hemisphere but especially on the mountains of central and eastern Asia. The bilaterally symmetrical flowers sometimes have very unusual shapes. The flowers of the little elephant (P. groenlandica), for example, resemble the head, trunk, and ears of an elephant. Louseworts are semiparasitic on the roots of other plants