''Lathraea'' (toothwort) is a small genus of five to seven species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s, native to temperate

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. They are

parasitic plant A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All Parasite, parasitic plants develop a specialized organ ...

s on the roots of other plants, and are completely lacking

chlorophyll Chlorophyll is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words (, "pale green") and (, "leaf"). Chlorophyll allows plants to absorb energy ...

. They are classified in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Orobanchaceae Orobanchaceae, the broomrapes, is a family (biology), family of mostly parasitic plants of the order (biology), order Lamiales, with about 90 genus, genera and more than 2000 species. Many of these genera (e.g., ''Pedicularis'', ''Rhinanthus'', ...

Etymology

The genus name ''Lathraea'' derives from the

ancient greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), 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 Rhinantheae is a tribe with fewer than 20 genera of herbaceous plants in the family Orobanchaceae. Phylogeny The phylogeny of the genera of Rhinantheae has been explored using DNA markers. Three assemblages can be distinguished in this trib ...

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 ''Bartsia'' is a genus of flowering plants in the family Orobanchaceae. Etymology ''Bartsia'' was named after Johann Bartsch (Latinized as Johannes Bartsius, 1709-1738), a botanist of Königsberg. The plant was named for him by his associate ...

'', ''

Euphrasia ''Euphrasia'', or eyebright, is a genus of about 215 species of Herbaceous plant, herbaceous flowering plants in the family (biology), family Orobanchaceae (formerly included in the Scrophulariaceae), with a cosmopolitan distribution. They are P ...

'', '' Tozzia'', ''

Hedbergia ''Hedbergia'' is a monotypic genus of flowering plants, initially classified in Scrophulariaceae, and now within the broomrape family Orobanchaceae. It contains a unique species, ''Hedbergia abyssinica''. It is an afromontane genus, widesprea ...

'', '' Bellardia'', and '' Odontites''. '' Melampyrum'' appears as a more distant relative.

Species

* Common toothwort ('' Lathraea squamaria'') is parasitic on the roots of hazel and

alder Alders are trees of the genus ''Alnus'' in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species ex ...

, occasionally on

beech Beech (genus ''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to subtropical (accessory forest element) and temperate (as dominant element of Mesophyte, mesophytic forests) Eurasia and North America. There are 14 accepted ...

, in shady places such as hedge sides. ''Lathraea squamaria'' is widespread in Europe. The common 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. * Purple toothwort ('' Lathraea clandestina'') grows on the roots mainly of alder, poplar and

willow Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

. At Arduaine Garden in Argyll in the absence of the three well-known hosts it grows on the roots of a variety of ornamental trees and shrubs; in the same garden cats are frequently seen to roll in the flowers and to eat them. It differs from common toothwort in the dark purple flowers being produced one on each stem. Purple toothwort grows in Middle and South Europe: Western Belgium, Western and Central France and Northern Spain, and locally in Central Italy.GRIN. Lathraea clandestina
Elsewhere, especially in the British Isles, the plant is locally naturalized in parks and old gardens and along river banks. *Rhodope toothwort ('' Lathraea rhodopaea'') is common in the Rhodope Mountains and

Rila Rila (, ) is the highest mountain range of Bulgaria, the Balkans, Balkan Peninsula, and Southeast Europe. It is situated in southwestern Bulgaria and forms part of the Rila–Rhodope Mountains, Rhodope Massif. The highest summit is Musala at an e ...

mountain range in southeastern Europe.

Cultural references

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.

Notes

References

Flora Europaea: ''Lathraea''

Flora of China: ''Lathraea''
{{Taxonbar, from=Q143696 Orobanchaceae Orobanchaceae genera Parasitic plants