''Mitrastemon'' is a genus of two widely disjunct species of parasitic plants. It is the only genus within the family Mitrastemonaceae. ''Mitrastemon'' species are root endoparasites, which grow on

Fagaceae The Fagaceae (; ) are a family of flowering plants that includes beeches, chestnuts and oaks, and comprises eight genera with around 1,000 or more species. Fagaceae in temperate regions are mostly deciduous, whereas in the tropics, many species ...

. It is also a non-photosynthetic plant that parasitizes other plants such as ''

Castanopsis sieboldii ''Castanopsis sieboldii'', also known as the Itajii chinkapin or Itajii, is a species of evergreen tree that lives in subtropical eastern Asia. This is a climax species that is commonly found in the Japanese temperate rainforest. Specimens are al ...

''.

History

The parasitic species, ''Mitrastemon yamamotoi'' was found in Japan in 1909. It was originally named ''Mitrastemma yamamotoi'' by botanist

Tomitaro Makino was a pioneer Japanese botanist noted for his taxonomic work. He has been called "Father of Japanese Botany", having been one of the first Japanese botanists to work extensively on classifying Japanese plants using the system developed by Carl ...

(1862 – 1957), but was later renamed as ''Mitrastemon yamamotoi'' in 1911. Then species ''Mitrastemon matudae'' was discovered by botanist Eizi Matuda during an expedition to Mt. Ovando (near the town of

Escuintla, Chiapas Escuintla is a town and municipality in the Mexican state of Chiapas, in southern Mexico. It covers an area of 206.2 km2. As of 2010, the municipality had a total population of 30,068, up from 28,064 as of 2005. As of 2010, the town of Esc ...

) in the state of Chiapas, Mexico (Matuda, 1947). The species was originally named by a botanist friend of Matuda, Yoshimatsu Yamamoto (1893-1947), in 1925–1926, but then published in 1936. ''Mitrastemon yamamotoi'' is a protandrous plant. Its flowers go through a male phase before transforming into their final female form. The flowers of ''M. yamamotoi'' attract a variety of insects ranging from wasps to flies and beetles. Among these, beetles are the best pollinators for this plant since their visit to the flower would pick up a large amount of pollen and they would pollinate from each of the flowers that they had already visited. The plant is endemic to tropical and subtropical forest regions such as southeast Asia and Japan.

Taxonomy

Originally ''Mitrastemon'' was placed within the order

Rafflesiales Rafflesiales is a botanical name of an order of flowering plants. The name was first published by Oliver in 1895. The Cronquist system used this name for an order placed in subclass Rosidae with the following circumscription (1981) : * order Ra ...

, together with other parasitic plants, but this order was long suspected to be actually polyphyletic. In 2004, the genus was found to be related to

Ericales The Ericales are a large and diverse order of flowering plants in the asterid group of the eudicots. Well-known and economically important members of this order include tea and ornamental camellias, persimmon, ebony, blueberry, cranberry, l ...

by comparing their

mitochondrial DNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...

. Several orthographic variants of the name ''Mitrastemon'' exist, including ''Mitrastema'' and ''Mitrastemma''. The correct taxonomic name is ''Mitrastemon'', the use of which was proposed and justified in an article by Reveal and approved by the Nomenclature Committee for Vascular Plants of the

International Association for Plant Taxonomy The International Association for Plant Taxonomy (IAPT) is an organization established to promote an understanding of plant biodiversity, facilitate international communication of research between botanists, and oversee matters of uniformity and ...

in a subsequent article. The species has a cylindrical body ranging from 3 cm to 7 cm in height with a tuberous base. During an early developmental stage it appears an off-white color; however, once it is dried it becomes a dark brown color (Mir ''et al''., 2016).

Life cycle

The plant is observed only during the winter season and it completes its visible life cycle from November to April (Mir ''et al''., 2016). ''Mitrastemon'' is completely embedded within the tissues of its host, except during the reproduction stage when above-ground parts emerge from host tissues.

Ecology

Unlike other plants, the flowers of this organism change sex from male to female. Various insects are involved in

pollination Pollination is the transfer of pollen from an anther of a plant to the stigma (botany), stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example bees, beetles or bu ...

. ''Mitrastemon yamamotol'' is mainly pollinated by social wasps, but previously unnoticed pollination are also important, based on visitation frequency and pollen loads. There have been studies of the pollination that suggest that nocturnal visitors, such as crickets and cockroaches, contribute to geitonogamous pollination. Diurnal visitors like social wasps facilitate outcrossing.

Species

There are two known species; *'' Mitrastemon matudae'' *'' Mitrastemon yamamotoi''

Distribution

''Mitrastemon yamamotoi'' is distributed in tropical and subtropical forests of Southeast Asia and Japan. ''Mitrastemon matudae'' is distributed from southern Mexico to Colombia.