Helonoma

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

Helonoma is a genus from the family of the orchid (Orchidaceae) only three or four kinds contains. They are common in tropical South America.

description

The Helonoma species are small, herbaceous plants that grow terrestrially . The roots are distributed in groups at short intervals on a creeping rhizome, they are slender, cylindrical, fleshy and hairy. The leaves are heaped in a rosette at the base of the shoot. They are clearly stalked, the leaf base includes the shoot. The leaf blade is oval and pointed, the leaves are dark green, the petiole whitish in color.

The terminal inflorescence is sparse and one-sided, it is hairy glandular. Some bracts sit at intervals on the peduncle, the lower ones surround it tubular, the upper ones are lanceolate. The small flowers stand out horizontally, they are green to white in color. The spindle-shaped ovary is sessile and hardly twisted. The sepals are shaped identically to each other, their basal half has grown together to form a tubular nectarium, the front part is somewhat spread out. The dorsal sepal is fused with the column , the lateral sepals are somewhat asymmetrically elongated at the base. The petals adhere to the dorsal sepal at least with the inner edge. The lip is narrowed (nailed) at the base-like, the nail is fused with the lateral sepals. The lip of the lip is arrow-shaped, adhering to the turned-up sides of the column. The club-shaped column is fused with the dorsal sepal up to the base of the stamen , at the base it extends beyond the base of the ovary (columnar foot). The scar is bilobed. The stamen is oval to lanceolate, dome-shaped, pointed at the front. It contains two elongated, club-shaped pollinia that hang from a small, round adhesive disc (Viscidium). The separating tissue between the stamen and stigma (rostellum) is short and blunt.

It is known from Helonoma bifida that the flowers are always self-pollinating. They lack the rostellum, and they are peloric .

Occurrence

Helonoma is known from a few locations in South America, mainly in the area of ​​the Guiana Shield. Altitudes of 1200 to 2600 meters are settled. The plants grow in permanently moist locations in moss pads.

Systematics and botanical history

Helonoma is classified within the tribe Cranichideae in the subtribe Spiranthinae . The genus was established by Garay in 1982. The name is derived from the Greek helonomos and means something like "growing in the swamp". Type species is Helonoma americana .

The genus Helonoma was considered a synonym for Cyclopogh by Burns-Balogh . Szlachetko, on the other hand, placed the species in Beloglottis . Szlachetko also newly established the genus Wallnoeferia with the only species Wallnoeferia peruviana . After Salazar , Wallnoeferia peruviana is another species of the genus Helonoma , but no one has yet published the required combination. Aracamunia liesneri could also be closely related to the genus Helonoma .

The species of the genus Helonoma :

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. 327-328 .
  • 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. 212-215 .

Individual evidence

  1. ↑ a b c d e Rafaël Govaerts (Ed.): Helonoma. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved December 8, 2016.

Further information