Northern Prairie Wildlife Research Center
A mid-May bloomer also called "wood-betony," Canada lousewort is restricted to the eastern one-fourth of North Dakota, but can be found from Quebec to Manitoba south to Mexico and Louisiana. The plant has been found in the mountains of Colorado to 10,000 feet elevation.
Canada lousewort is a native perennial, often arising from stolons. Up to five stems usually form a clump about a foot tall. Hairs are sparse at the stem bases, but turn into a wooly mass just below the flowers that overtop the leaves. Leaves are alternate, mostly basal, and about 3 inches long. Leaf blades are wavy-edged and pinnately dissected. Upper leaves are about an inch long. Flowers are about an inch long, pale yellow, and sometimes carry a purplish petal. About 10-20 flowers form a cluster about 2 inches long. Half-inch long capsules contain the seeds.
Look for Canada lousewort in low sandy soils in the prairie or in moist open woods. There are no known economic uses for this species. One Arctic Pedicularis has been used as food, and the powdered leaves of an Oriental species are reported to be used to induce elimination of blood from the respiratory tract. I have not seen Canada lousewort in heavily grazed areas, but have found it in the spring in prairies mowed the previous summer.
Canada lousewort is a member of the figwort family (Scrophulariaceae) which derives its name from the supposed cure of scrophula and figwarts attributed to members of this group by the early herbalists. There are over 300 species of Pedicularis worldwide, all in the northern hemisphere. About 65 species occur in North America. Pedicularis is from the Latin pediculus "a louse" because of the early European belief that cattle, feeding where lousewort abounded, became covered with lice. Canadensis means Canadian in botanical Latin. Canada lousewort was first described for science in 1767 by Carl von Linne (Linneaus) the Swedish father of modern plant taxonomy.