Lathraea

Lathraea (toothwort) is a small genus of five to seven species of flowering plants, native to temperate Europe and Asia. They are parasitic plants on the roots of other plants, and are completely lacking chlorophyll. They are classified in the family Orobanchaceae.
The toothwort is a protocarnivorous plant. Most of the plant consists of a branched whitish underground stem closely covered with thick fleshy colourless leaves, which are bent over so as to hide the under surface; irregular cavities communicating with the exterior are formed in the thickness of the leaf. On the inner walls of these chambers are stalked hairs, which when stimulated by the touch of an insect send out delicate filaments by means of which the insect is killed and digested.
Etymology.
The genus name "Lathraea" derives from the ancient greek (), meaning "clandestine", which is a reference to the fact that it is inconspicuous until it flowers.
Phylogeny.
The phylogeny of the genera of Rhinantheae has been explored using molecular characters. "Lathraea" is the sister genus to "Rhinanthus", and then to "Rhynchocorys". These three genera share phylogenetic affinities with members of the core Rhinantheae: "Bartsia", "Euphrasia", "Tozzia", "Hedbergia", "Bellardia", and "Odontites". "Melampyrum" appears as a more distant relative.
Species.
In Pavel Ivanovich Melnikov's "In the Forests" a Russian wise woman ("znakharka") calls this plant Peter's Cross and says it protects against devils but only if collected with a prayer to God.