Cyclopogon

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Cyclopogon
Cyclopogon bicolor, illustration from "The Botanical Register"

Cyclopogon bicolor , illustration from "The Botanical Register"

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

Cyclopogon is a genus from the family of the orchid (Orchidaceae). It contains more than ninety types of herbaceous plants that are native to tropical America.

description

The species of the genus Cyclopogon form strongly compressed shoots on a rhizome , which above ground produce a rosette of leaves and below ground a tuft of fleshy, hairy, spindle-shaped or cylindrical roots . The stalked leaves are oval to lanceolate in shape, pointed at the end. In some species the leaves are brownish, light green, white or dark green stripe patterns appear quite often on the leaves.

The terminal, racemose inflorescence is covered with bracts at intervals and hairy at least in the upper part. The resupinated flowers are one-sided in some species. They are somewhat drooping, fleshy, tubular, often fragrant. There are greenish, whitish or brownish colors, the lip is white, often with darker markings. The ovary is cylindrical to slightly spindle-shaped, sessile or very short-stalked, hairy, somewhat twisted and curved. The sepals are free or fused tubular at the base. All three sepals are somewhat bowl-shaped at their base, with only the two at the side enclosing a nectarium. The petals lie against the dorsal sepal. The lip is abruptly narrowed (“nailed”) at the base, followed by two laterally directed nectar glands. The middle part of the lip is shaped like a groove, the sides are turned up and cling to the column . The front part of the lip is widened again after a constriction, often somewhat three-lobed, covered with calluses or hair. The column is club-shaped with a short "column foot". The sessile stamen is oval with a membranous extension at the tip, it contains two pollinia . These are furrowed lengthways, of a floury consistency, they hang over with a small stalk each on a shared adhesive disc (Viscidium). The scar distinguishable or merging areas. The dividing tissue between the stamen and stigma (rostellum) is elongated, fleshy, it ends bluntly.

In some species, bees from the Halictidae family ( Augochloropsis , Dialictus , Pseudoaugochloropsis ) have been observed as pollinators. The pollinia cling to the head. Due to the floury, crumbly consistency, several flowers can be pollinated with one pollinium.

The known chromosome numbers vary over a wide range from 2n = 28, 30, 32, 45, 56 and 66.

Occurrence

Cyclopogon is common in tropical America. From Florida and Mexico in the north, the genus occurs across Central America and the Caribbean to Argentina and Uruguay in the south. Altitudes up to 3000 meters are settled. Cyclopogon obliquus occurs adventively in Southeast Asia.

The locations are diverse: in addition to moist forests, there are also species that occur in savannas, grasslands, swamps or moors. Most species grow terrestrially, but there are some epiphytes .

Systematics and botanical history

Cyclopogon is classified within the tribe Cranichideae in the subtribe Spiranthinae . The genus was classified by Burns-Balogh in the so-called Pelexia group, which Szlachetko regarded as a separate subtribe Cyclopogoninae. Recent studies have identified Pelexia and Sarcoglottis as related genera .

Cyclopogon was first described by Presl in 1827 . The name Cyclopogon is made up of the Greek words κύκλος cyclos , "circle" and πώγων pogon , "beard". The reference is unclear, Garay explains, pogon means something like "fire tail with split ends", which describes the reddish inner petals of dried herbarium specimens that protrude from the circle of the outer ones. Type species is Cyclopogon ovalifolius .

Garay saw the difference between the type species and the other species of the genus as so serious that he established a new genus Beadlea for the latter . Later authors argued that with this difference - the degree of intergrowth of the petals - there were smooth transitions and no sharp dividing line between genera. Other genera that have been proposed as separate are Cocleorchis and Warscaea (mostly used as synonyms) and Stigmatosema .

The species of the genus Cyclopogon :

Cyclopogon congestus
Blossom of Cyclopogon elatus
Cyclopogon lindleyanus

See also

literature

  • James D. Ackerman: Cyclopogon . Edited by Flora of North America Editorial Committee. In: Flora of North America . tape 26 . New York / Oxford 1993, p. 520 f . ( efloras.org [accessed February 6, 2008]).
  • Leslie A. Garay: 225 (1). Orchidaceae (Cypripedioideae, Orchidoideae and Neottioideae) . Edited by Gunnar Harling, Benkt Sparre. In: Flora of Ecuador . tape 9 , 1978, ISSN  0347-8742 , p. 258 .
  • Leslie A. Garay: A generic revision of the Spiranthinae . In: Botanical Museum Leaflets / Harvard University . tape 28 , no. 4 , 1982, ISSN  0006-8098 , pp. 298-299, 308-309 .
  • 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 / Oxford 2003, ISBN 0-19-850711-9 , pp. 188-192 .

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, ISSN  0002-9122 , p. 777-795 .
  2. ↑ a b c d e f g h i j k l m Rafaël Govaerts (Ed.): Cyclopogon. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved March 29, 2020.

Web links

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