any of a genus (Pedicularis) of perennial plants of the figwort family, with pinnately divided leaves and spiked clusters of yellow, rose, or purple flowers
See lousewort in American Heritage Dictionary 4
(lousˈwûrtˌ, -wôrtˌ)
noun
Any of numerous plants of the genus Pedicularis, having clusters of irregular, variously colored flowers. Also called wood betony.