Apostasia (orchid)
Apostasia wallichii
Apostasia is a genus of the orchid family ( Orchidaceae). It consists of eight or nine species of herbaceous plants that are native to tropical Southeast Asia.
Description
The species of the genus Apostasia form a creeping rhizome, which is surrounded by low dry leaves. The roots are thin, surrounded by velamen radicum, they form small, rounded nodules. The roots arise not only along the rhizome, but also from the above-ground shoot, where they break through the leaf bases.
The ascending, sometimes branched shoots bear leaves in a loose rosette or evenly distributed on the shoot. The leaves are lanceolate to narrowly oval shaped. The leaf base cuneate to run into an indistinct petiole, which includes the shoot and completely veiled. The leaf blade is quite smooth and not crinkled along the Vein. At the blade tip, the leaf margins have grown together into a thin tube.
The most branched, Prone to hanging inflorescence appears terminal. The bracts are much shorter than the ovary. The short flower stalk goes seamlessly into the long, narrow ovary. The flowers appear 'upside. The petals are free from fleshy texture, somewhat boat-shaped bent and white, cream colored or yellow. Sepals and petals are hardly different, even a specialization of petals as lip is hardly noticeable, but the flowers are nearly radial symmetry. The column is formed from the fused at the base with one another stamens and style. There are two fertile stamens and in some species a third barren ( Staminodium ) available. The resulting capsule fruit is cylindrical in shape, with three longitudinal ribs.
Occurrence
Apostasia is widespread in tropical Southeast Asia. The northern distribution limit runs from Northeast India through southern China. A disjoint, even further north situated deposit is located on the Japanese Ryukyu Islands. Southeast Windwärts the area over Indo-China, Indonesia, the Philippines extends to New Guinea and northeastern Australia. Also a disjoint area is located in Sri Lanka. Apostasia species come from the coast to about 1700 meters altitude before. Apostasia wallichii is the type with the largest circulation.
The sites are mostly in the shade of evergreen, moist forests.
Systematics and botanical history
Apostasia together with the genus Neuwiedia own subfamily within the orchids that Apostasioideae. This subfamily is the sister group to all other orchids. Within the genus can be two different sections, the section Apostasia with an existing Staminodium and section Adactylus without Staminodium.
The genus Apostasia was erected in 1825 by Carl Ludwig Blume. The type species is Apostasia odorata. The name Apostasia comes from the Greek and means " difference " or "divorce", which is intended to indicate the differences with the other orchids.
The following species are counted to Apostasia:
- Apostasia elliptica J.J.Sm.
- Apostasia latifolia Rolfe
- Apostasia nipponica Masam.
- Apostasia nuda R.Br.
- Apostasia odorata flower
- Apostasia parvula Schltr.
- Apostasia ramifera S.C.Chen & K.Y.Lang
- Apostasia shenzhenica Z.J.Liu & L.J.Chen
- Apostasia wallichii R.Br.
Documents
The information in this article come from mainly:
- Alec M. Pridgeon, Phillip J. Cribb, Mark W. Chase and Finn N. Rasmussen ( ed.): Genera Orchidacearum. General Introduction, Apostasioideae, Cypripedioideae. 1, Oxford University Press, New York and Oxford 1999, ISBN 0-19-850513-2, pp. 100-104.
- Xinqi Chen, Zhu Guanghua, Ji Zhanhe, long Kaiyong, Luo Yibo, Phillip Cribb: Orchidaceae. In: Wu Zhengyi, Peter H. Raven (eds.): Flora of China. Vol 25, Missouri Botanical Garden Press, St. Louis 1994 ( http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=102345, accessed 14 November 2009 ).
- EF de Vogel: Monograph of the Tribe Apostasieae ( Orchidaceae). In: Blumea. 17, No. 2, 1969, pp. 313-350.
Furthermore, quoting:
Postgraduate
- List of Orchid Genera
- Commons: Apostasia - album with pictures, videos and audio files
- Apostasia
- Apostasioideae ( orchids)
- Apostasioideae