Deiregyne

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Deiregyne
Deiregyne eriophora in the Mexican state of Tlaxcala

Deiregyne eriophora in the Mexican state of Tlaxcala

Systematics
Order : Asparagales (Asparagales)
Family : Orchids (orchidaceae)
Subfamily : Orchidoideae
Tribe : Cranichideae
Sub tribus : Spiranthinae
Genre : Deiregyne
Scientific name
Deiregyne
Schltr.

Deiregyne is a genus from the family of the orchid (Orchidaceae). It contains 24 species that are native to Central America.

description

The species of the genus Deiregyne are terrestrial, small, perennial , herbaceous plants. The roots arise in clusters at the base of the shoot, they are fleshy, bulbous, thickened, glabrous or hairy. The leaves are close together in a rosette, less often they are distributed in the lower part of the shoot. The leaf shape is oval to lanceolate, the leaf base is wedge-shaped without a stalk into a sheath surrounding the stalk. By the time of flowering, which falls in the dry season, the leaves have already withered.

The terminal, upright inflorescence is few to many-flowered, the flowers are arranged on one side in some species. The peduncle is hairy and covered by bracts . These are tubular, pointed, and are translucent with darker, brown veins. The bracts look similar. The resupinated flowers are white, yellow or light green, the base of the lip is often colored differently and drawn darker. Many species produce fragrance during the day. The ovary is cylindrical to spindle-shaped, hairy, sometimes twisted. It points upwards at an acute angle to the inflorescence axis; the transition to the flower cover is curved so that the flowers are roughly horizontal. The sepals are shaped roughly the same, the outer sides are hairy. The edges of the three outer petals are at least at the base together and form a tube, the tips are turned back. The lateral sepals run down asymmetrically at the base of the extension of the column (column foot) and form a protruding nectarium with it. The dorsal sepal is fused with the column at the base. The petals adhere to the dorsal sepal. The lip is divided into three parts: at the base it is abruptly narrowed, there are two nectar glands, the outside is hairy, the sides turned up. The middle part is wider, the sides of the are turned up runny and stick to the column. The front part is also wide, the tip is bent down. The column is curved or straight, at the base it protrudes beyond the point of attachment on the ovary (column foot). The oval to semicircular scar is bilobed. The separating tissue between the stigma and the stamen (rostellum) is soft, elongated, triangular in shape, blunt to slightly pointed, ending with three pointed teeth. The stamen is oval, with a thick stalk that is completely fused with the clinandrium . The pollinia are narrow-club-shaped and hang on a small, round to tongue-shaped adhesive disc (Viscidium).

Bumblebees ( bombus ) are suspected to be pollinators .

Occurrence

Deiregyne is common in Mexico, Costa Rica, El Salvador, Nicaragua, Guatemala, and Honduras. They occur at altitudes from 1000 to 3200 meters. The locations are oak and pine-oak forests, tropical dry forests, dry shrubbery and grasslands.

Systematics and botanical history

Deiregyne is classified within the tribe Cranichideae in the subtribe Spiranthinae . The genus was described by Rudolf Schlechter in 1920, the type species , Deiregyne diaphana , was determined by Leslie Garay . Burns-Balogh suggested a different type because, in their opinion, Garay's definition did not coincide with Schlechter's original description. Garay's Aulosepalum hemichrea served her as a type species for the genus Deiregyne . As a result, almost all species of the genus Aulosepalum were described as Deiregyne by her . Other botanists argue that Schlechter's vague descriptions fit a large number of related orchids and could not serve as a basis, therefore Garay's type species and classifications are to be regarded as valid.

The genera Dichromanthus , Mesadenus and Schiedeella are closely related to Deiregyne .

The name Deiregyne is made up of the Greek words deire , "neck" and gyne , "woman". It refers to the bend at the top of the ovary.

The majority of all species occur only in Mexico; a few also in other countries in Central America. Here are the species of the genus Deiregyne :

supporting documents

Most of the information in this article comes from:

  • Leslie A. Garay: A generic revision of the Spiranthinae . In: Botanical Museum Leaflets of Harvard University . tape 28 , no. 4 , 1982, pp. 311-312 .
  • Alec M. Pridgeon, Phillip Cribb, Mark W. Chase, Finn Rasmussen (Eds.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae . tape 3/2 . Oxford University Press, New York and Oxford 2003, ISBN 0-19-850711-9 , pp. 193-196 .

Individual evidence

  1. ↑ Gerardo A. Salazar, Mark W. Chase, Miguel A. Soto Arenas, Martin Ingrouille: Phylogenetics of Cranichideae with emphasis on Spiranthinae (Orchidaceae, Orchidoideae): evidence from plastid and nuclear DNA sequences . In: American Journal of Botany . tape 90 , 2003, p. 777-795 ( amjbot.org ).
  2. ↑ a b c d e f Rafaël Govaerts (Ed.): Deiregyne. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved July 10, 2018.

Further information

Web links

Commons : Deiregyne  - album with pictures, videos and audio files