Mesadenella
Mesadenella cuspidata
Mesadenella is a genus of the orchid family ( Orchidaceae). It contains seven species that are native to tropical America.
Description
The Mesadenella species are herbaceous plants that individual species vary in size, they grow terrestrial or lithophytic. Some species form an underground rhizome, roots arise in bunches, they are fleshy, fusiform, glabrous or hairy. The leaves are in a basal rosette. They are stalked or run at the base to wedge-shaped. The leaf blade is ovate to lanceolate vice versa. The leaf surface is bright sometimes mottled or covered by a network of dark-colored veins.
The terminal, racemose inflorescence is glandular hairy at the top. Some bracts envelop him partially. The numerous flowers are small and inconspicuous, its color is white, whitish- green and brown. The hairy bracts are lanceolate. The also hairy ovary is sessile, scarcely twisted, having inclined upwards. The sepals are hairy on the outside, to form a tube, only the tips are curved slightly outwardly. The upward-pointing ( dorsal) sepal is lanceolate, the lateral sepals are slightly askew at the base, decurrent on the column and with this a depression ( mentum) forming. The petals are the dorsal sepal and stick with their inner edges there on, their tops are free. The lip is narrowed significantly to the base ( pinned ) with two arrow-shaped rear facing nectar glands. The leaf surface of the lip is rinnig, the sides are bent up and adhere to the column. The column is short, club-shaped, on the bottom with a longitudinally extending groove, there hairy at the base with a curved foot. The scar is bilobed and v -shaped. The stamen is in outline narrow -ovate, base rounded, forward it ends pointed. It contains the lanceolate to clavate pollinia attached to a common viscid disc ( Viscidium ) depend. The separation layers between stamen and stigma ( rostellum ) is stiff, somewhat cartilaginous, oblong, pointed. The capsule fruit is oval.
Occurrence
Mesadenella comes in tropical America from Mexico in the north to southern Brazil, northern Argentina and Paraguay before. The species grow in the shade of forests, in humid climates or always with a short dry season. They are often found on river banks or temporarily flooded sites. They come right up to altitudes of 800 meters.
Systematics and botanical history
Mesadenella is classified within the tribe Cranichideae in the subtribe Spiranthinae. The genus was described in 1952 by Pabst and Garay. The name The name is a diminutive of Mesadenus and refers to the resemblance of the Pollinariums the two genera. Lectotype Mesadenella is esmeraldae, a synonym of Mesadenella cuspidata.
The genus Mesadenella is closely related to the genera Eltroplectris and Sacoila. While Balogh looked 1982 Mesadenella only as a section of a broad genus Stenorrhychos, Szlachetko Mesadenella divided further by Mesadenella atroviridis separated out as a separate genus Garaya.
The following species are included in genus Mesadenella:
- Mesadenella angustisegmenta Garay
- Mesadenella atroviridis ( Barb.Rodr. ) Garay
- Mesadenella cuspidata ( Lindl. ) Garay
- Mesadenella meeae R.J.V.Alves
- Mesadenella peruviana Garay
- Mesadenella tonduzii ( Schltr. ) Pabst & Garay
- Mesadenella variegata D.E.Benn. & Christenson