Skeptrostachys
Illustration of Skeptrostachys rupestris (Fig. I) and Skeptrostachys balanophorostachya (Fig. IV)
Skeptrostachys is a genus of the orchid family ( Orchidaceae). It contains 13 species that are native to South America.
Description
The Skeptrostachys species are herbaceous plants. On a short rhizome roots are in clumps, rarely distributed along the rhizome. They are fleshy, thickened stalked cylindrical, glabrous or hairy. The leaves are distributed in the lower part of the stem, rarely they form a basal rosette. In its heyday, they are often already wilted. The leaf shape is oval to lanceolate, the leaf base cuneate to run, there is no petiole. The leaf margins are slightly translucent.
The terminal, racemose inflorescence is hairy at the top. The peduncle is covered by ciliated bracts. The numerous, closely spaced flowers are 'upside down meaty, no fragrance, its color is white, light green, yellow or red. The green or red - brown bracts are often ciliated. The hairy ovary is oval to spindle-shaped, often slightly asymmetrical in shape. The sepals are hairy on the outside, abut each other to form a tube, their tips are bent back slightly. The upward-pointing ( dorsal) sepal is hood -shaped, the lateral sepals are fused together at their base asymmetric, and for a short distance, so they form together with the pedestal a bulge. The petals lie on the dorsal sepal and stick with their inner edges there on. The lip is sitting at the base wedge-shaped with thickened edges ( nectaries ), hairiness on both sides. The leaf surface of the lip, seen from the side, curved S-shaped. The sides are bent up and adhere to the column, the lip ends rounded and scalloped edge. The column is short, cylindrical and glabrous at the base of the joint with the ovary in projection ( " pedestal " ), this pedestal fused with a piece of the ovary, then a short piece free. The scar is semi-circular to V -shaped, it is parallel to the column or has slightly forward. The stamen is in outline oval or lanceolate, forward it ends pointed. It contains the narrow club-shaped, longitudinally furrowed pollinia attached to a common oblong shaped viscid disc ( Viscidium ) depend. The separation layers between stamen and stigma ( rostellum ) is stiff, pointed, narrowly triangular shaped, with two lateral teeth at the base. The capsule fruit is obovate.
In Skeptrostachys paraguayensis a chromosome number of 2n = 46 was found with a pair of chromosomes is significantly larger than all the others.
Occurrence
Skeptrostachys is widespread in southeastern Brazil, as well as in neighboring Argentina, Paraguay and Uruguay. They come right up to altitudes of 1600 meters. They colonize open grasslands, savannah and swamps.
Systematics and botanical history
Skeptrostachys is classified within the tribe Cranichideae in the subtribe Spiranthinae. The genus was described in 1982 by Leslie A. Garay. The name derives from the Greek σκῆπτρον skeptron for " scepter " and στάχυς stachys, " ear ", and refers to the appearance of the inflorescence. Type species is Skeptrostachys rupestris.
The genus Skeptrostachys was cleaved from Stenorrhynchos. Similarities to the genus Sacoila.
The following species are included in genus Skeptrostachys:
- Skeptrostachys arechavaletanii ( Barb.Rodr. ) Garay
- Skeptrostachys balanophorostachya ( Rchb.f. & hot. ) Garay
- Skeptrostachys berroana ( Kraenzl. ) Garay
- Skeptrostachys congestiflora ( Cogn. ) Garay
- Skeptrostachys correana Szlach.
- Skeptrostachys disoides ( Kraenzl. ) Garay
- Skeptrostachys gigantea ( Cogn. ) Garay
- Skeptrostachys latipetala ( Cogn. ) Garay
- Skeptrostachys montevidensis ( Barb.Rodr. ) Garay
- Skeptrostachys paraguayensis ( Rchb.f. ) Garay
- Skeptrostachys paranahybae ( Kraenzl. ) Garay
- Skeptrostachys rupestris ( Lindl. ) Garay
- Skeptrostachys stenorrhynchoides Szlach.