Cyrtorchis
Introduction Photo of ''Cyrtorchis praetermissa'' Summerh. growing on a rock at the foot of the Mulanje Massif in MalawiShift in floral colouration from white to orange in an ''Cyrtorchis arcuata'' subsp. ''arcuata '' inflorescence due to senescence, which is characteristic for this genus''Cyrtorchis crassifolia'' Schltr. '''''Cyrtorchis''''' is a genus of flowering plants from the orchid family Orchidaceae native to Africa.
Description The species of the genus ''Cyrtorchis'' are epiphytic or lithophytic herbs, which do not have pseudobulbs. The white, fragrant, star-shaped flowers are distinctly spurred.
Cytology The diploid chromosome count of ''Cyrtorchis arcuata'' is 2n = 46.
Physiology ''Cyrtorchis'' is known to utilize the crassulacean acid metabolism, which entails photosynthesis during the daytime, and gaseous exchange through open stomata during the night. This enables the plant to save water.
Etymology The generic name ''Cyrtorchis'' is composed of the Greek words "kirtos" meaning curved and "orchis" meaning testicles, which refers to orchids.
Taxonomy The genus has been proven to be monophyletic.===Sections===The genus has been divided into the sections ''Cyrtorchis'' section ''Homocolleticon'' Summerh. and ''Cyrtorchis'' section ''Cyrtorchis'' based on differences in the shape of the viscidium. Originally the section ''Cyrtorchis'' was published as section ''Heterocolleticon'' Summerh., but it is now known as ''Cyrtorchis'' section ''Cyrtorchis''. The section ''Homocolleticon'' is characterized by an uniformly textured viscidium, in contrast to the viscidium of section ''Cyrtorchis'', which consists of two distinct zones.The section ''Homocolleticon'' Summerh. was elevated to a genus by Szlach. & Olszewski in 2001, but ''Homocolleticon'' (Summerh.) Szlach. & Olszewski is now a synonym of ''Cyrtorchis'' Schltr.===Species===As of December 2022, there are 19 currently accepted species:# ''Cyrtorchis arcuata'' (Lindl.) Schltr.# ''Cyrtorchis aschersonii'' (Kraenzl.) Schltr.# ''Cyrtorchis brownii'' (Rolfe) Schltr.# ''Cyrtorchis chailluana'' (Hook.f.) Schltr.# ''Cyrtorchis crassifolia'' Schltr. in R.E.Fries# ''Cyrtorchis erythraeae'' (Rolfe) Schltr.# ''Cyrtorchis glaucifolia'' Summerh.# ''Cyrtorchis guillaumetii'' (Pérez-Vera) R.Rice# ''Cyrtorchis hamata'' (Rolfe) Schltr.# ''Cyrtorchis henriquesiana'' (Ridl.) Schltr.# ''Cyrtorchis injoloensis'' (De Wild.) Schltr.# ''Cyrtorchis letouzeyi'' Szlach. & Olszewski# ''Cyrtorchis monteiroae'' (Rchb.f.) Schltr.# ''Cyrtorchis neglecta'' Summerh.# ''Cyrtorchis okuensis'' Droissart, Azandi & M.Simo# ''Cyrtorchis praetermissa'' Summerh.# ''Cyrtorchis ringens'' (Rchb.f.) Summerh# ''Cyrtorchis seretii'' (De Wild.) Schltr.# ''Cyrtorchis submontana'' Stévart, Droissart & Azandi===Species formerly placed in ''Cyrtorchis''===*''Cyrtorchis cufodontii'' Chiov. is now considered to be a synonym of ''Ypsilopus amaniensis'' (Kraenzl.) D'haijère & Stévart*''Cyrtorchis refracta'' (Kraenzl.) Schltr. is now considered to be a synonym of ''Ancistrorhynchus refractus'' (Kraenzl.) Summerh.
Ecology ===Habitat===It grows in dense forests and rainforests, as well as in plantations. It is found growing on tree trunks and branches, which receive high levels of sunlight. In addition to epiphytic growth, it can also grow as a lithophyte attached to rocks.===Pollination===Several hawk moth species of the genus ''Hippotion'' have been identified as likely pollinators of ''Cyrtorchis okuensis''.The white flowers shift to an orange pollination after pollination or senescence. Such post-pollination behaviour is not uncommon, and it may be explained by a reduced attractivity of flowers to pollinators, if the flowers are no longer viable.
Conservation Two species, namely ''Cyrtorchis letouzeyi'' Szlach. & Olszewski and ''Cyrtorchis henriquesiana'' (Ridl.) Schltr., have been categorized as species of least concern (LC) under the IUCN Red List criteria. ''Cyrtorchis arcuata'' subsp. ''arcuata'' has been categorized as a Least Concern species by the Red List of South African Plants. Another species, ''Cyrtorchis glaucifolia'' Summerh., has been categorized as an endangered (EN) species under the IUCN Red List criteria, and ''Cyrtorchis okuensis'' Droissart, Azandi & M.Simo is categorized as Near Threatened (NT).
Horticulture ''Cyrtorchis'' is easy to cultivate in well drained substrate. ''Cyrtorchis arcuata'' is most commonly found in private collections.
See also * List of Orchidaceae genera
References
External links **