Microthelys
Microthelys is a genus of the orchid family ( Orchidaceae). It contains seven species that are mainly distributed in Central America.
Description
The Microthelys species are small herbaceous plants that grow terrestrial or occasionally epiphytic. The roots are fleshy, spindle-shaped to bulbous and hairy. One to three leaves are in a basal rosette, flowering time, they are often already wilted. The leaves are petiolate, the petiole includes the shoot. The leaf blade is narrow oval to lanceolate and ends in a point, the leaf surface is dull green.
The racemose inflorescence is sometimes hairy at the top. He is enveloped by tubular bracts. The glabrous bracts are oval and pointed end. The ovary is sessile, cylindrical to spindle- shaped and has obliquely upward. The numerous, sometimes fragrant flowers are small, their color is whitish or greenish, sometimes with reddish proportions, especially on the lip. The flowers are tubular and have an angle to the ovary down or be horizontal. Sepals which are each formed almost the same, they are approximately parallel to each other to form a tube, only the tips are curved slightly outwardly. The dorsal sepal is slightly concave and grown for a piece of the column. The lateral sepals are fused together at the base for a short distance and set with slate base of the pedestal. The petals are the dorsal sepal and stick with their inner edges there on, their tops are free. The lip at its base for a short distance narrowed ( " nailed " ), in some species there with two rear facing nectar glands. The leaf surface of the lip is rinnig, the sides are bent up and adhere to the column. Centered on the lip there are two to four thickened, red-colored spots. The column is club-shaped, at the base of them joint with the ovary reaching out ( pedestal ). In hand, it is provided with a longitudinal groove and hairy. The scar is roundish or transversely to the column axis slightly elongated shape. The stamen is oval, pointed toe or rounded. It contains the narrow club-shaped, yellow pollinia, hang on a common, small, round viscid disc ( Viscidium ). The separation layers between stamen and stigma ( rostellum ) is flat and barely recognizable. The capsule fruit is oval.
Occurrence
Microthelys occurs mainly in Central America from Mexico to Costa Rica. Microthelys intagana is known from Ecuador, Microthelys rubrocallosa achieved in Northern New Mexico. All species occur at higher altitudes before 2000-3600 meters. They grow in montane forests, thickets and in open, rocky places.
Systematics and botanical history
Microthelys is classified within the tribe Cranichideae in the subtribe Spiranthinae. The genus was described in 1982 by Leslie Garay. The name comes from the Greek words μικρός micros, "small", and θῆλυς thelys, "female", together. It refers to the very small rostellum. Type species is Microthelys minutiflora.
The genus Microthelys is closely related to some species of the genus Funkiella and Schiedeella. Also Stalkya from Venezuela is Microthelys very similar. Balogh introduced in 1982 Microthelys species in the genera Brachystele and Schiedeella while Szlachetko treated her in 1991 as a section of Galeottiella, but later recognized again as a separate genus.
The following species are included in genus Microthelys:
- Microthelys constricta ( Szlach. ) Szlach.
- Microthelys hintoniorum ( Todzia ) Szlach. , Rutk. & Mytnik
- Microthelys intagana ( Dodson & Dressler ) Szlach.
- Microthelys markowskiana ( Szlach. ) Szlach.
- Microthelys minutiflora ( A.Rich. & Galeotti ) Garay
- Microthelys nutantiflora ( Schltr. ) Garay
- Microthelys rubrocallosa ( BLRob. & Greenm. ) Garay