Palmorchis
Palmorchis pubescentis ( as a synonym Rolfea elata )
The genus Palmorchis from the orchid family (Orchidaceae ) consists of 21 species. They are found in tropical South and Central America.
Description
The Palmorchis species are herbaceous, sometimes woody at the base, up to a meter high plants. They grow terrestrial, Palmorchis imuyanensis also semi -aquatic. The roots are clumps together and are thick, but not thickened. The shoot is thin, erect, leafy at the top. The leaves are short-stalked, oval, pointed to long drawn out ending. They are along the leaf veins crinkled ( Plikat ).
The flowers of a population often appear simultaneously and are short-lived. The racemose or branched inflorescences can only terminally combined only in the leaf axils or both appear. The bracts of the flowers are just folded along the midrib ( konduplikat ). The small flowers are 'upside, the petals form a tube, but are not fused together. To the lip, the petals are shaped similarly to each other, the petals are slightly shorter and narrower than the outer petals. The lip is fused at the base with the column. It is three-lobed, the side lobes are erect, parallel to the column or include. The middle lobe is much smaller, the leaf surface is covered with ridges or warts. The column is slender and curved. The stamen at the end of the column is bent down towards the column axis. It is hardly covered by fabric of the column. It contains four pear-shaped pollinia, the cohesion of the pollen is not particularly strong, but the consistency is not too mealy. The pollinia possess neither stalks nor Klebdrüse. The scar is oval shaped and lies transversely to the column axis; it is surrounded by a raised edge. The separation between scar tissue and stamen ( rostellum ) is short. The capsule fruit is fleshy, the column remains liable up to the maturity of the fruit. Hold the seeds, in contrast to most other orchids, a hard seed coat.
Dissemination
The species of the genus Palmorchis are widespread in tropical South America. In the north, the area extends as far as Central America and reached Costa Rica and Nicaragua. In the south, the area extends approximately to the Amazon. There are colonized at altitudes of 1000 meters forests.
Ecology
In three Palmorchis species from Panama could be observed that the flowers by bees of the genus Trigona Osiris and be visited. An actual pollination by Osiris could be detected in Palmorchis nitida.
The fleshy fruits and the hard seed coat may indicate a endozoochore spread.
Systematics and botanical history
The classification of the genus within the subfamily Palmorchis Epidendroideae has long been unclear. As related genera Sobralia and Elleanthus, Diceratostele or because comparable Vanilla seeds have been proposed. Dressler arranged them in a separate tribe, the Palmorchideae, a. According to recent DNA studies it is counted for tribes Neottieae. It is probably the sister group of all other Neottieae; alternatively, the Palmorchis - line could even branch off before the Neottieae:
Palmorchis
Remaining Neottieae
Remaining Epidendroideae
Palmorchis
Neottieae
Remaining Epidendroideae
The genus was described in 1877 by João Barbosa Rodrigues. Lectotype is Palmorchis pubescentis. The name Palmorchis refers to the similarity of plants of the genus Geonoma palm trees.
Meanwhile, 21 valid species are known:
- Palmorchis caxiuanensis Rocha
- Palmorchis colombiana Garay
- Palmorchis deceptorius Veyret & Szlach.
- Palmorchis eidae Dressler
- Palmorchis guianensis ( Schltr. ) C.Schweinf. Correll &
- Palmorchis imuyaensis Dodson & G.A.Romero
- Palmorchis lobulata ( Mansf. ) C.Schweinf. Correll &
- Palmorchis nitida Dressler
- Palmorchis pabstii Veyret
- Palmorchis paludicola Dressler
- Palmorchis pandurata C.Schweinf. Correll &
- Palmorchis powellii ( Ames) C.Schweinf. Correll &
- Palmorchis prospectorum Veyret
- Palmorchis puber ( Cogn. ) Garay
- Palmorchis pubescentis Barb.Rodr.
- Palmorchis silvicola L.O.Williams
- Palmorchis sobralioides Barb.Rodr.
- Palmorchis sordida Dressler
- Palmorchis trilobulata L.O.Williams
- Palmorchis trinotata Dressler