Codonorchis

Codonorchis lessonii

Codonorchis is a genus of the orchid family ( Orchidaceae). With two species colonized the temperate South America. They are small, perennial, herbaceous plants. The genus Codonorchis forms a separate tribe Codonorchideae.

Description

The terrestrially growing plants have underground storage organs, which consist partly of root tissue, partly of shoot tissue. By stolons at which produce daughter tubers, they can reproduce vegetatively. The roots are fibrous and surrounded by velamen. The shoot bears in the lower third two to four true leaves, the - are arranged lively - rare in orchids. The leaves are oval or slightly spatulate, horizontal spread and hairless. Between leaf and stem tissue is no separation.

About the leaves to the stem axis is continued as einblütiger inflorescence. The ovary is not stalked, plump and short. The support sheet is slightly longer than the ovary. The flowers are 'upside, the petals are not fused together. The lip is abruptly narrowed at the base ( " nailed " ) and there fused with the column. The lip is slightly three-lobed, the sides are wrapped around the column to the top. The front portion of the lip is bent downward. Along the central veins of the lip sit tiny little head - or mushroom-shaped appendages. The edges of the lip can be curled slightly. The column is long and thin, bent, winged approximately semicircular and narrow in cross section. The stamen is located at the end of the column and is bent down towards the column axis. The stamen remains there even when removing the pollinia on the column. The two pollinia are shaped yellow and oblong. The pollen is as individual pollen grains ( monads ) that this measure about 30 microns in diameter and have no opening ( inaperturat ). The scar is located anteriorly ( in the resupinierten flower at the bottom of the column), it is unlobed, oblong arranged along the column axis. The fruit capsule is upright.

Dissemination

The two species of the genus Codonorchis are distributed in temperate and subtropical South America. Codonorchis lessonii occurs in Chile, Argentina and the Falkland Islands. Codonorchis canisioi inhabited a small distribution area in southern Brazil.

Both species occur in the shadow of moist forests. They survive the unfavorable season with their underground tubers.

Systematics and botanical history

The genus Codonorchis was established by Lindley in 1840. The name comes from the Greek words codon, " bell ", and orchis, " testicles " (here: " Orchid" ), together. It refers to the shape of the small appendage on the lip. Lindley had only the type Codonorchis lessonii known, had already been described under other generic names of d' Urville and Brongniart. The second species was described in 1936 by Mansfeld.

Bad arranged the genus Codonorchis 1926 in the tribe Diurideae. Their systematic position within this tribe has long been unclear: Evil put them in the subtribe Caladeniinae, Brieger wanted to set up its own subtribe Codonorchidinae, Dressler put them in the Chloraeinae.

First molecular genetic studies have shown that Codonorchis is not very close related to the tribe Diurideae. It represents within the subgenus Orchidoideae is a basal group for those of Cribb own tribe, the Codonorchideae, was erected.

Documents

The information in this article come from:

• Alec M. Pridgeon, Phillip Cribb, Mark W. Chase and Finn Rasmussen ( ed.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae. 3/2, Oxford University Press, New York and Oxford 2003, ISBN 0-19-850711-9, pp. 17ff.

Furthermore, quoting:

Postgraduate

• List of Orchid Genera
• Commons: Codonorchis - album with pictures, videos and audio files

• Orchids
• Orchidaceae