any of various N temperate scrophulariaceous plants of the genus Pedicularis, having spikes of white, yellow, or mauve flowers
See also betony (sense 3)
lousewort in American English
(ˈlaʊsˌwɜrt)
noun
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
Word origin
so called because sheep feeding on the plants were said to become infested with vermin