Amitostigma
Encyclopedia
Amitostigma 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
orchids, including some myco-heterotrophic species. The globose or ovoid tuber
s (1 to 1.5 centimetres) of these autotrophic plants are fleshy and not lobed, with several slender root
s. New shoots grow each tuber.
The 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 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
. The erect anthers are cohesive with the column through its broad base or back. They have two parallel locules with farinaceous, sectile pollinia
. The small rostellum
is beak-shaped, attached with its folded end to the viscidium. The two protruding stigmas are slightly club-shaped.
The 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.
Orchidaceae
The Orchidaceae, commonly referred to as the orchid family, is a morphologically diverse and widespread family of monocots in the order Asparagales. Along with the Asteraceae, it is one of the two largest families of flowering plants, with between 21,950 and 26,049 currently accepted species,...
).
It is an exclusively Asian genus of 27 orchids, growing in the alpine habitats of east Asia, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, eastern Himalaya, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
to Kuril Islands
Kuril Islands
The Kuril Islands , in Russia's Sakhalin Oblast region, form a volcanic archipelago that stretches approximately northeast from Hokkaidō, Japan, to Kamchatka, Russia, separating the Sea of Okhotsk from the North Pacific Ocean. There are 56 islands and many more minor rocks. It consists of Greater...
. Twenty two species of this genus grow in China.
These are dwarf terrestrial
Terrestrial plant
A terrestrial plant is one that grows on land. Other types of plants are aquatic , epiphytic , lithophytes and aerial ....
orchids, including some myco-heterotrophic species. The globose or ovoid tuber
Tuber
Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...
s (1 to 1.5 centimetres) of these autotrophic plants are fleshy and not lobed, with several slender root
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
s. New shoots grow each tuber.
The stem
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
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
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
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
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is racemose, seldom subcapitate. The floral bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s are often lanceolate. The cylindrical to fusiform ovary
Ovary
The ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in anatomically female individuals are analogous to testes in anatomically male individuals, in that they are both gonads and endocrine glands.-Human anatomy:Ovaries...
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
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s are completely separate from each other, with an oblong to ovate appearance, and usually singly veined. The erect petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
s are straight, often slightly broader than the sepals.
The three- or four-lobed lip
Labellum
Labellum is the Latin diminutive of labium, meaning lip. These are anatomical terms used descriptively in biology, for example in Entomology and botany.-Botany:...
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
Column (botany)
The column, or technically the gynostemium, is a reproductive structure that can be found in several plant families: Aristolochiaceae, Orchidaceae, and Stylidiaceae....
. The erect anthers are cohesive with the column through its broad base or back. They have two parallel locules with farinaceous, sectile pollinia
Pollinium
Pollinium, or plural pollinia, is a coherent mass of pollen grains in a plant.They are the product of only one anther, but are transferred, during pollination, as a single unit. This is regularly seen in plants such as orchids and many species of milkweeds .Most orchids have waxy pollinia...
. The small rostellum
Rostellum
The rostellum is a projecting part of the column in Orchidaceae flowers, and separates the male stamen from the female gynoecium, commonly preventing self-fertilisation...
is beak-shaped, attached with its folded end to the viscidium. The two protruding stigmas are slightly club-shaped.
The capsule
Capsule (fruit)
In botany a capsule is a type of simple, dry fruit produced by many species of flowering plants. A capsule is a structure composed of two or more carpels that in most cases is dehiscent, i.e. at maturity, it splits apart to release the seeds within. A few capsules are indehiscent, for example...
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.
List of species
- Amitostigma alpestre Fukuy., Bot. Mag. (Tokyo) 49: 664 (1935).
- Amitostigma amplexifolium Tang & F.T.Wang, Bull. Fan Mem. Inst. Biol. 7: 3 (1936).
- Amitostigma basifoliatum (Finet) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 92 (1919).
- Amitostigma bifoliatumAmitostigma bifoliatumAmitostigma bifoliatum is a species of plant in the Orchidaceae family. It is endemic to China.-References:* China Plant Specialist Group 2004. . Downloaded on 20 August 2007....
Tang & F.T.Wang, Bull. Fan Mem. Inst. Biol. 7: 127 (1936). - Amitostigma capitatumAmitostigma capitatumAmitostigma capitatum is a species of plant in the Orchidaceae family. It is endemic to China.-References:* China Plant Specialist Group 2004. . Downloaded on 20 August 2007....
Tang & F.T.Wang, Bull. Fan Mem. Inst. Biol. 7: 4 (1936). - Amitostigma dolichocentrum Tang, F.T.Wang & K.Y.Lang, Acta Phytotax. Sin. 20: 84 (1982).
- Amitostigma faberi (Rolfe) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 93 (1919).
- Amitostigma farreri Schltr., Repert. Spec. Nov. Regni Veg. 20: 378 (1924).
- Amitostigma gonggashanicum K.Y.Lang, Acta Phytotax. Sin. 22: 312 (1984).
- Amitostigma gracile (Blume) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 93 (1919).
- Amitostigma keiskeiAmitostigma keiskeiAmitostigma keiskei is a species of plant in the Orchidaceae family....
(Finet) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 93 (1919). - Amitostigma keiskeoides (Gagnep.) Garay & Kittr., Bot. Mus. Leafl. 30: 181 (1985 publ. 1986).
- Amitostigma kinoshitae (Makino) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 93 (1919).
- Amitostigma lepidumAmitostigma lepidumAmitostigma lepidum is a species of plant in the Orchidaceae family....
(Rchb.f.) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 94 (1919). - Amitostigma monanthum (Finet) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 94 (1919).
- Amitostigma papilionaceum Tang, F.T.Wang & K.Y.Lang, Acta Phytotax. Sin. 20: 83 (1982).
- Amitostigma parciflorum (Finet) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 94 (1919).
- Amitostigma physoceras Schltr., Acta Horti Gothob. 1: 133 (1924).
- Amitostigma pinguicula (Rchb.f. & S.Moore) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 94 (1919).
- Amitostigma simplexAmitostigma simplexAmitostigma simplex is a species of plant in the Orchidaceae family. It is endemic to China.-References:* China Plant Specialist Group 2004. . Downloaded on 20 August 2007....
Tang & F.T.Wang, Bull. Fan Mem. Inst. Biol. 10: 25 (1940). - Amitostigma tetralobumAmitostigma tetralobumAmitostigma tetralobum is a species of plant in the Orchidaceae family. It is endemic to China.-References:* China Plant Specialist Group 2004. . Downloaded on 20 August 2007....
(Finet) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 95 (1919). - Amitostigma thailandicum Seidenf. & Thaithong in G.Seidenfaden, Contr. Orchid Fl. Thailand 13: 8 (1997).
- Amitostigma tibeticum Schltr., Repert. Spec. Nov. Regni Veg. 20: 379 (1924).
- Amitostigma tominagae (Hayata) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 4: 95 (1919).
- Amitostigma trifurcatum Tang, F.T.Wang & K.Y.Lang, Acta Phytotax. Sin. 20: 80 (1982).
- Amitostigma wenshanense W.H.Chen, Y.M.Shui & K.Y.Lang, Acta Bot. Yunnan. 25: 521 (2003).
- Amitostigma yueanum Tang & F.T.Wang, Bull. Fan Mem. Inst. Biol. 10: 26 (1940).