Microthelys

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Microthelys
Systematics
Order : Asparagales (Asparagales)
Family : Orchids (orchidaceae)
Subfamily : Orchidoideae
Tribe : Cranichideae
Sub tribus : Spiranthinae
Genre : Microthelys
Scientific name
Microthelys
Garay

Microthelys is a genus from the family of the orchid (Orchidaceae). It contains seven species that are mainly found in Central America .

description

The Microthelys species are small, herbaceous plants that grow terrestrially or occasionally epiphytically . The roots are fleshy, spindle-shaped to bulbous and hairy. One to three leaves are in a basal rosette, and by the time they bloom they are often withered. The leaves are petiolate, the petiole includes the shoot. The leaf blade is narrow oval to lanceolate and ends in a tip, the leaf surface is dull green.

The racemose inflorescence is sometimes hairy in the upper area. It is covered by tubular bracts . The hairless bracts are oval and pointed. The ovary is sessile, cylindrical to spindle-shaped and points diagonally upwards. The numerous, occasionally fragrant flowers are small, their color is whitish or greenish, sometimes with reddish parts, especially on the lip . The flowers are tubular and point downwards at an angle to the ovary or are horizontal. The sepals are shaped pretty much the same, they are roughly parallel to each other and thus form a tube, only the tips are slightly curved outwards. The dorsal sepal is somewhat concave and fused to the column for a part. The lateral sepals are fused together for a short distance at the base and start at the base of the column with a slanted base. The petals lie against the dorsal sepal and adhere with their inner edges there, their tips are free. The lip is narrowed ("nailed") for a short distance at its base, in some species there with two nectar glands pointing backwards. The spread of the lip is runny, the sides are bent upwards and adhere to the column . In the middle of the lip there are two to four thickened, red-colored areas. The column is club-shaped, reaching at the base beyond the point of attachment at the ovary (column foot). On the underside it is provided with a longitudinal furrow and hairy. The scar is rounded or somewhat elongated across the axis of the column. The stamen is oval, pointed or rounded at the front. It contains the narrow, club-shaped, yellow pollinia that hang on a common, small, round adhesive disc (Viscidium). The separating tissue between the stamen and the stigma (rostellum) is flat and hardly noticeable. The capsule fruit is oval.

Occurrence

Microthelys occur mainly in Central America from Mexico to Costa Rica. Microthelys intagana is known from Ecuador, Microthelys rubrocallosa reaches New Mexico in the north . All species occur at higher altitudes from 2000 to 3600 meters. They grow in montane forests, bushes and in open, rocky places.

Systematics and botanical history

Microthelys is classified within the tribe Cranichideae in the subtribe Spiranthinae . The genus was described by Leslie Garay in 1982 . The name is made up of the Greek words μικρός micros , "small", and θῆλυς thelys , "female". It refers to the very small rostellum. Type species is Microthelys minutiflora .

The genus Microthelys is closely related to some species in the genus Funkiella and Schiedeella . Also Stalkya from Venezuela is microthelys very similar. In 1982 Balogh placed the Microthelys species in the genera Brachystele and Schiedeella , while Szlachetko treated them as a section of Galeottiella in 1991 , but later recognized them again as a separate genus.

The following species are included in the genus Microthelys :

literature

  • Leslie A. Garay: A generic revision of the Spiranthinae . In: Botanical Museum Leaflets of Harvard University . tape 28 , no. 4 , 1982, pp. 336-337 .
  • Alec M. Pridgeon, Phillip Cribb, Mark W. Chase, Finn Rasmussen (Eds.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae . tape 3 . Oxford University Press, New York and Oxford 2003, ISBN 0-19-850711-9 .

Individual evidence

  1. ↑ a b c d e f g h i Rafaël Govaerts (ed.): Microthelys. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved July 16, 2018.
  2. ↑ Phil ton: microthelys rubrocallosa (Green medusa orchid). In: nmrareplants.unm.edu. New Mexico Rare Plant Technical Council, 2008, accessed November 19, 2009 .
  3. ^ A b Gerardo Salazar: Microthelys . In: Genera Orchidacearum . Vol. 3, pp. 227-229.

Further information