Lousewort (genus Pedicularis), herbaceous plant of figwort family (Scrophulariaceae). Five hundred species occur in the Northern Hemisphere; 22 throughout Canada. Most Canadian species are perennial; heights vary (10-100 cm). Louseworts occur in alpine situations and in damp, marshy ground in association with grasses. They are semiparasitic: green leaves produce some food and suckers connect to, and absorb food from, grass roots. Parrot-beaked, often brightly coloured flowers usually occur in showy, terminal spikes. P. arctica, with pink flowers on stout stems (up to 15 cm), are often abundant in alpine situations. P. groenlandica, common in boggy areas, grows to 50 cm and has reddish purple flowers. Common lousewort or wood betony (P. canadensis), now considered poisonous, was eaten and used as animal feed by settlers. North American Indians used it for food, to cure rattlesnake bite, to reduce swellings, and as an aphrodisiac.