Platanthera
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The genus Platanthera belongs to the subfamily Orchidoideae of the family Orchidaceae, and is comprised of about 100 species of orchids. The members of this genus were previously included in the genus Orchis, which is a close relative (along with the genus Habenaria). They are distributed throughout the temperate regions of the Northern Hemisphere. They are terrestrial and have tubercules.
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[edit] Etymology
Orchids obtain their name of Greek "orchis", meaning "testicle", for the appearance of the underground tubercles in some terrestrial species. The word "orchis" used Theophrastus for the first time (371/372 - 287/286 B.C.), in his book "De Historia Plantarum" (On the Natural History of Plants). He was student of Aristotle and it is considered the father of botany and ecology.
The name Platanthera comes from the Greek and means "ample anther," referring to to the separation of the base of the pollen nodes.
Platanthera was previously classified within the genus Orchis.
[edit] Range
These orchids may be found distributed about the subarctic and temperate zones of the Northern Hemisphere: from Scandinavia to North Africa, Madeira, Iceland, Asia Minor, Russia, the Himalayas, North America and Alaska. 10 species may be found in Wisconsin alone.
[edit] Description & Habitat
These terrestrial orchids develop in basic soils within moist marches, on forest edges, and in clearings within the forest. Their large tuberculous roots store a great quantity of water, which allows them to survive in times of drought.
Platanthera may be distinguished from Orchis and Habenaria by the absence of stigmatic processes, the presence of a nectariferous spur (which attracts pollinating insects), and the ovoid, tuberculous shape of the roots.
Platantheras have large, oblong or ovoid leaves, becoming lanceolate at the distal end. They develop a short shoot which can achieve a height of 30-40 cm. The leaves above the shoot are shorter than the ones below.
The inflorescence is a cylindric shoot, with 5-25 small, fragrant flowers developing from axillary buds. They flower at the end of Spring, or during Summer.
[edit] Species of Platanthera
Many species can cross-fertilise, resulting in great morphologic variety and complicating classification.
The type species is Platanthera bifolia (L.) Rich. 1817
More than 400 species, subspecies, and varieties have been described, of which 85 are clearly defined. Most of this are found distributed about Asia.
52 species from temperate Asian countries (China, Japan, Korea, Taiwan) 13 species from tropical Asian countries (Burma, Indonesia, Papua New Guinea, the Phillipines) 37 species from North America north of Mexico 7 species from Europe
- Europe:
- Platanthera algeriensis
- Platanthera bifolia
- Platanthera chlorantha
- Platanthera holmboei
- Platanthera hyperborea
- Platanthera obtusata var. oligantha
- Azores
- Platanthera azorica
- Platanthera micrantha
- North Africa:
- Platanthera algeriensis
- Platanthera kuenkelei
- North America:
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- Asia:
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[edit] References
- Leroy-Terquem, Gerald and Jean Parisot. Orchids: Care and Cultivation. London: Cassel Publishers Ltd., 1991.
- Schoser, Gustav. Orchid Growing Basics. New York: Sterling Publishing Co., Inc., 1993.
- White, Judy. Taylor’s Guide to Orchids. Frances Tenenbaum, Series Editor. New York: Houghton-Mifflin, 1996.
- The Illustrated Encyclopedia of Orchids by Alec Pridgeon. Published by the Timber Press.
- The Manual Of Cultivated Orchid Species By Bechtel, Cribb and Launert, Published by The MIT Press.
