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2007-06-26T06:31:08Z

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{{Taxobox
| color = lightgreen
| name = Amitostigma
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Monocotyledon|Liliopsida]]
| ordo = [[Asparagales]]
| familia = [[Orchidaceae]]
| subfamilia = [[Orchidoideae]]
| tribus = Orchideae
| subtribus = Orchidinae
| alliance = Orchis
| genus = '''''Amitostigma'''''
| genus_authority = [[Rudolf Schlechter|Schltr.]]
| subdivision_ranks = Species
| subdivision =
See text.
}}

'''''Amitostigma''''' [[Friedrich Schlechter|Schltr.]] 1919, is a genus in the orchid family ([[Orchidaceae]]).

It is an exclusively Asian genus of 27 orchids, growing in the alpine habitats of east Asia, [[India]], eastern [[Himalaya]], [[China]], and [[Japan]] to [[Kuril Islands]]. Twenty two species of this genus grow in China.

These are dwarf [[terrestrial plant |terrestrial]] orchids, including some [[myco-heterotrophic]] species. The globose or ovoid [[tuber]]s (1 to 1.5 [[centimetre]]s) of these autotrophic plants are fleshy and not lobed, with several slender [[root]]s. New shoots grow each tuber.

The [[Plant stem|stem]] is usually erect, with one (or rarely two or three) basal or cauline (stem) leaves. The length of the stem can vary between 5 and 45 centimetres.

The green [[leaf]] blade is not articulate and can have an oblong, lanceolate, elliptic, or ovate form, even within the same species (see ''A. lepidum''). The leaves appear at the time of expansion of the flower (anthesis).

The terminal [[inflorescence]] is racemose, seldom subcapitate. The floral [[bract]]s are often lanceolate. The cylindrical to fusiform [[ovary]] is resupinate (turned upside down).

Each inflorescence shows many (rarely one or two) flowers. These are also resupinate and usually twisted to one side.

The [[sepal]]s are completely separate from each other, with an oblong to ovate appearance, and usually singly-veined. The erect [[petal]]s are straight, often slightly broader than the sepals.
The three- or four-lobed [[labellum|lip]] is usually longer and broader than the petals and sepals, spurred at the base. The mid-lobe is oblong, square, or ovate. The margin of the lip is often slightly undulate.

They have a characteristic short [[column (botany)|column]]. The erect [[anther]]s are cohesive with the column through its broad base or back. They have two parallel locules with farinaceous, sectile [[pollinium|pollinia]]. The small [[rostellum]] is beak-shaped, attached with its folded end to the viscidium. The two protruding [[carpel|stigma]]s are slightly club-shaped.

The [[capsule (fruit)|capsule]] is suberect.

The color may vary within the same species: ''Amitostigma lepidum'' may show a purple lip with white margins, or a white lip with purple dots or a totally white lip. Even the leaves may vary from lanceolate to ovate within the same species.

After flowering, the leaves turn yellow color and die off. The plants then starts its summer dormancy for several months. This cycle is well adapted to a climate which is hot and dry in summer.

== Species ==
* ''Amitostigma alpestre'' : Alpine Chicken Orchid (Taiwan).
* ''Amitostigma amplexifolium'' (SC. China)..
* ''Amitostigma basifoliatum'' (China).
* ''Amitostigma bifoliatum'' (China).
* ''Amitostigma capitatum'' (China) .
* ''Amitostigma dolichocentrum'' (China) .
* ''Amitostigma faberi'' (China)
* ''Amitostigma farreri'' (Tibet)..
* ''Amitostigma gonggashanicum'' (China).
* ''Amitostigma gracile'' (China to Temp. E. Asia).
* ''Amitostigma keiskei'' (Japan)
* ''Amitostigma keiskeoides'' (Vietnam).
* ''Amitostigma kinoshitae'' (S. Kuril Is., Japan - Hokkaido, N. Honshu).
* ''Amitostigma kurokamianum'' (Japan - Kyushu: Mt. Kurokami).
* ''Amitostigma lepidum'' : Okinawa Orchid (Japan - S. Kyushu to Nansei-shoto.
* ''Amitostigma monanthum'' (SE. Tibet to C. China).
* *''Amitostigma monanthum'' var. ''forrestii'' (Tibet). Tuber geophyte
* *''Amitostigma monanthum'' var. ''monanthum'' (SE. Tibet to C. China). Tuber geophyte
* ''Amitostigma papilionaceum'' (China - NW. Sichuan).
* ''Amitostigma parciflorum'' (China).
* ''Amitost
igma physoceras'' (China - Sichuan)..
* ''Amitostigma pinguicula'' (China).
* ''Amitostigma simplex'' (hina - W. Sichuan, SW. Yunnan)..
* ''Amitostigma tetralobum'' (China - SW. Sichuan, N. Yunnan).
* ''Amitostigma thailandicum'' (Thailand).
* ''Amitostigma tibeticum'' (Tibet).
* ''Amitostigma tominagai'' (Taiwan).
* ''Amitostigma trifurcatum'' (China)..
* ''Amitostigma yueanum'' (China - Yunnan).

[[Category:orchid genera]]

Amitostigma - Revision history

MediaWiki default at 06:31, 26 June 2007