the unkindly named lousewort. It is a parasitical plant that uses grass roots to obtain nutrients, and was blamed for causing attacks of lice in livestock. It thrives in marshy boggy places and may therefore have been associated with liver flukes, and fluke infested sheep often have lice. The flower looks very similar in shape to purple toothwort (qv) another parasitical plant. I wonder if they are related species or if there has been some independent evolution towards a similar shape.