''Didymoplexis'', commonly known as crystal orchids or as 双唇兰属 (shuang chun lan shu), is a genus of terrestrial leafless orchids in the family Orchidaceae, about twenty species of which have been described. Orchids in this genus have swollen, fleshy

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

s and thin, pale, upright fleshy flowering stems with

resupinate Resupination is derived from the Latin word ''resupinus'', meaning "bent back with the face upward" or "on the back". "Resupination" is the noun form of the adjective "resupine" which means "being upside-down, supine or facing upward". The word " ...

, bell-shaped white or pale yellowish brown flowers. They are native to Africa, Madagascar, Southeast Asia,

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and various islands of the Pacific.

Description

Orchids in the genus ''Didymoplexis'' are small, leafless, terrestrial,

mycotrophic A mycotroph is a plant that gets all or part of its carbon, water, or nutrient supply through symbiotic association with fungi. The term can refer to plants that engage in either of two distinct symbioses with fungi: *Many mycotrophs have a mut ...

herbs In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...

with a swollen, fleshy rhizome. The flowering stem is thin, upright and fleshy with a few scale-like

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

s fleshy and one to a few flowers. The flowers are resupinate, white or pale yellowish brown and often last for less than a day. The sepals and

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s are joined at the base to form a short, bell-shaped tube with the tips spreading widely. The labellum is relatively broad and has a band of calli along its midline.

Taxonomy and naming

The genus ''Didymoplexis'' was first formally described in 1843 by William Griffith and the description was published in the ''Calcutta Journal of Natural History''. The name ''Didymoplexis'' is derived from the Ancient Greek ''didymos'' meaning "double" or "twin" and ''plexis'' meaning "twine", "twist" or "weave" referring to the interlocking calli on the labellum.

List of species

The following is a list of species of ''Didymoplexis'' recognised by the World Checklist of Selected Plant Families as at October 2018: * ''

Didymoplexis africana ''Didymoplexis'', commonly known as crystal orchids or as 双唇兰属 (shuang chun lan shu), is a genus of terrestrial leafless orchids in the family Orchidaceae, about twenty species of which have been described. Orchids in this genus have ...

Summerh. Victor Samuel Summerhayes (21 February 1897 – 27 December 1974) was an English botanist in charge of the orchid herbarium at Royal Botanical Gardens, Kew for 39 years. Summerhayes was born on 21 February 1897 at Street, Somerset and he was ...

- Ghana, Ivory Coast, Congo-Brazzaville, Congo-Kinshasa, Tanzania * ''

Didymoplexis avaratraensis ''Didymoplexis'', commonly known as crystal orchids or as 双唇兰属 (shuang chun lan shu), is a genus of terrestrial leafless orchids in the family Orchidaceae, about twenty species of which have been described. Orchids in this genus have ...

* ''

Didymoplexis cornuta ''Didymoplexis'', commonly known as crystal orchids or as 双唇兰属 (shuang chun lan shu), is a genus of terrestrial leafless orchids in the family Orchidaceae, about twenty species of which have been described. Orchids in this genus have ...

'' P.J.Cribb - Java, Borneo ** ''Didymoplexis cornuta'' var. ''betungkerihunensis'' Tsukaya & H.Okada ** ''Didymoplexis cornuta'' var. ''cornuta'' ** 'Didymoplexis cornuta'' var. ''maliauensis'' Tsukaya,

Suleiman Suleiman (Arabic language, Arabic: سُلِيمَان ''sulaymān''; or dictionary.reference.comsuleiman/ref>) is the Arabic name of the Quranic king and Islam, Islamic prophet Solomon (name), Solomon meaning "man of peace", derived from the Heb ...

& H.Okada * '' Didymoplexis flexipes''

J.J.Sm. Johannes Jacobus Smith (Antwerp 29 June 1867 – Oegstgeest 14 January 1947) (sometimes written as Joannes Jacobus Smith) was a Dutch Botany, botanist who, between years 1905 to 1924, crossed the islands of the Dutch East Indies (mainly Java (isl ...

- Java * '' Didymoplexis himalaica''

Schltr. Friedrich Richard Rudolf Schlechter (16 October 1872 – 16 November 1925) was a German taxonomist, botanist, and author of several works on orchids. He went on botanical expeditions in Africa, Indonesia, New Guinea, South and Central America a ...

- Assam, Bhutan * '' Didymoplexis latilabris''

- Kalimantan * '' Didymoplexis micradenia'' (

Rchb.f. Heinrich Gustav Reichenbach (Dresden, 3 January 1823 – Hamburg, 6 May 1889) was a botanist and the foremost German orchidologist of the 19th century. His father Heinrich Gottlieb Ludwig Reichenbach (author of ''Icones Florae Germanicae et Helve ...

)

Hemsl. William Botting Hemsley (29 December 1843, in East Hoathly – 7 October 1924, in Kent) was an English botanist and 1909 Victoria Medal (horticulture), Victoria Medal of Honour recipient. He was born in East Hoathly, Sussex and in 1860 started wo ...

- Taiwan, Vietnam, Java, Maluku, New Guinea, Solomons, Fiji, Niue, New Caledonia, Samoa, Tonga, Samoa, Wallis & Futuna, Micronesia * '' Didymoplexis minor''

- Java * '' Didymoplexis obreniformis''

- Java ** ''Didymoplexis obreniformis'' var. ''maliauensis'' Suetsugu,

& Tsukaya ** ''Didymoplexis obreniformis'' var. ''obreniformis'' * '' Didymoplexis pachystomoides'' ( F.Muell.) Garay & W.Kittr. - Queensland * ''

Didymoplexis pallens ''Didymoplexis pallens'', commonly known as crystal bells or 双唇兰 (shuang chun lan), is a leafless terrestrial mycotrophic orchid in the family Orchidaceae. It has up to fifteen small, white, pinkish or brownish flowers on a fleshy yellow ...

'' Griff. - Asia, Southeast Asia,

and some Pacific and Indian Ocean islands * ''

Didymoplexis philippinensis ''Didymoplexis'', commonly known as crystal orchids or as 双唇兰属 (shuang chun lan shu), is a genus of terrestrial leafless orchids in the family Orchidaceae, about twenty species of which have been described. Orchids in this genus have ...

'' Ames - Philippines * '' Didymoplexis recurvata'' P.J.Cribb - Philippines * '' Didymoplexis seidenfadenii'' C.S.Kumar & Ormerod - Kerala * '' Didymoplexis sirichaii'' Suddee * '' Didymoplexis striata''

- Java, Borneo * '' Didymoplexis torricellensis''

- New Guinea * '' Didymoplexis trukensis'' Tuyama - Micronesia * '' Didymoplexis verrucosa'' J.Stewart & Hennessy - KwaZulu-Natal, Madagascar * '' Didymoplexis vietnamica'' Ormerod - Guangxi, Vietnam

Distribution and habitat

Crystal orchids grow in grassy forest, bamboo thickets and rainforest in India, southern

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

and Indochina to southern

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

and the Philippines, throughout the

Malay Archipelago The Malay Archipelago (Indonesian/Malay: , tgl, Kapuluang Malay) is the archipelago between mainland Indochina and Australia. It has also been called the " Malay world," "Nusantara", "East Indies", Indo-Australian Archipelago, Spices Archipe ...

to New Guinea, Christmas Island, tropical Australia, and the southwest

Pacific islands Collectively called the Pacific Islands, the islands in the Pacific Ocean are further categorized into three major island groups: Melanesia, Micronesia, and Polynesia. Depending on the context, the term ''Pacific Islands'' may refer to one of se ...

. Some also occur in South West Africa and Madagascar.

References

External links

IOSPE orchid photos, ''Didymoplexis pallens''Swiss Orchid Foundation at the Herbarium Jany Renz, ''Didymoplexis pallens'' Griff.Photo of ''Didymoplexis verrucosa'' in South Africa
{{Taxonbar, from=Q2159150 Gastrodieae genera Gastrodieae Myco-heterotrophic orchids