Louseworts are all partial parasites. One used to believe that livestock were infested with louse when they ate these plants, which explains the name. Louseworts belonged to the the figwort family, but since recently it has been accepted by many plant authorities as a genus of the broomrape family. The only two lousewort species found in the lowlands of Northwestern Europe are the common and marsh lousewort. Both species form winter buds. Their seeds do not remain long viable. While common lousewort seeds can wait up to two years to germinate, marsh lousewort seeds hardly last longer than one season.