Coeloglossum

Frog orchid or
long-bracted orchid
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Genus: Coeloglossum
Species: C. viride
Binomial name
Coeloglossum viride
Synonyms
  • Dactylorhiza viridis (L.) R.M.Bateman, Pridgeon & M.W.Chase
  • Satyrium viride L.
  • Orchis viridis (L.) Crantz
  • Habenaria viridis (L.) R.Br. in W.T.Aiton
  • Gymnadenia viridis (L.) Rich.
  • Sieberia viridis (L.) Spreng.
  • Entaticus viridis (L.) Gray
  • Chamorchis viridis (L.) Dumort.
  • Platanthera viridis (L.) Lindl.
  • Himantoglossum viride (L.) Rchb.
  • Peristylus viridis (L.) Lindl.

Coeloglossum is a genus of orchids. It has long been considered to have only one species, Coeloglossum viride, the frog orchid. Some recent classifications regard Coeloglossum as part of the larger genus, Dactylorhiza, so that C. viride becomes Dactylorhiza viridis.[1][2][3] Other sources continue to keep Coeloglossum viride separate.[4][5]

Under either name, the species has a wide distribution across the cooler parts of the Northern Hemisphere, covering much of Europe, non-tropical Asia (Russia, Japan, China, the Himalayas, etc.), much of Canada and parts of the United States (Alaska, Northeast, the Appalachians, Great Lakes Region, Northern Great Plains, and Rocky Mountains).[2][6][7][8] It is typically found growing in moist, rich soil in wet meadows, moist or wet deciduous woods and thickets,[9] and is frequently found on steep slopes.

Etymology

The generic name Coeloglossum is derived from the Greek koilos glossum meaning "hollow tongue", referring to the hollow spur on the tongue-like labellum.[10]

Description

Plant arises from fleshy, forked roots and ranges in height from 10–55 cm. The leaves of C. viride are 5–14 cm long and 2–7 cm wide; leaves at the base of the orchid are obovate to elliptical, while leaves higher on the stem become lanceolate. Two to six leaves are found on one plant, and leafing is alternate.

Inflorescence of the orchid is a dense raceme (spike-like cluster) containing 7 to 70 small flowers. Flowers are greenish in color, and often tinged with purple, reddish, or red-brown color. Flowers are subtended by conspicuous long, tapering bracts which are 1–6 cm long, with the lower bracts longer and typically greatly exceeding the length of the flower. Sepals are oval with little or no point, 3–7 mm long and 2–4 mm wide and dark green. Sepals join with petals to form a hood opposite the lower petal of the flower. Petals are long and narrow, 3.5–5 mm long and about 0.5 mm wide, and curve inwards. The lower petal is strap-shaped and usually split at the very tip to form two or three tooth-like divisions, with the middle tooth smaller than the others. It is 5–11 mm long and 1–4 mm wide. A 2–3 mm long nectar spur projects behind the labellum.[11]

Coeloglossum viride flowers in late May and early June. It is either pollinated by bees and small wasps, or reproduces autogamously by incoherent pollinia.[10]

In North America, Coeloglossum viride can be mistaken for Platanthera flava (the pale green orchid), but can be best distinguished by the labellum, which is notched at the apex and does not have the tubercle of P. flava.

Uses

Coeloglossum viride var. bracteatum is being investigated as a potential candidate for the treatment of vascular dementia.[12][13]

Chemistry

The chemistry of Coeloglossum viride var. bracteatum is complex, featuring a wealth of bioactive constituents, at least seven of which are new to science and peculiar to the plant. Known compounds found thus far to be present are 4-hydroxybenzaldehyde, 4-hydroxybenzyl alcohol (=Gastrodigenin), 4,4'-dihydroxydibenzyl ether, 4,4'-dihydroxydiphenylmethane (see Xenoestrogen), 4-(4-hydroxybenzyloxy)benzyl alcohol, gastrodin, quercetin-3,7-diglucoside (see Flavonol glycoside), thymidine, loroglossin, militarine, dactylorhin A, dactylorhin B, β-Sitosterol and daucosterol.[14]

References

  1. ↑ Bateman, R.M. (2009). "Evolutionary classification of European orchids: the crucial importance of maximising explicit evidence and minimising authoritarian speculation". Journal Europäischer Orchideen. 41: 243–318.
  2. 1 2 "Dactylorhiza viridis". World Checklist of Selected Plant Families. Royal Botanic Gardens, Kew.
  3. ↑ Chen, Xinqi; Gale, Stephan W. & Cribb, Phillip J. "Dactylorhiza viridis". Flora of China. 25. pp. 115, 117.
  4. ↑ Sheviak, Charles J. & Catling, Paul M. "Coeloglossum viride". Flora of North America. 26. p. 580.
  5. ↑ Stace, Clive (2010). New Flora of the British Isles (3rd ed.). Cambridge, UK: Cambridge University Press. p. 870. ISBN 978-0-521-70772-5.
  6. ↑ "World Checklist of selected plant families TDWG Geocodes" (PDF). Retrieved 2013-06-03.
  7. ↑ Biota of North America Program, 2013 county distribution map
  8. ↑ Altervista Flora Italiana, Celoglosso Long Bract Frog Orchid, Coeloglossum viride (L.) Hartm., Accepted name: Dactylorhiza viridis (L.) R. M. Bateman, Pridgeon & M. W. Chase includes European distribution map
  9. ↑ "NPWRC :: Aquatic and Wetland Vascular Plants". Npwrc.usgs.gov. 2013-02-02. Retrieved 2013-06-03.
  10. 1 2 "Coeloglossum viride (L.) Hartm. var. virescens (Muhl.) Luer". Botany.wisc.edu. Retrieved 2013-06-03.
  11. ↑ "Coeloglossum viride: UW-Stevens Point Freckmann Herbarium: Plant Details Page". Wisplants.uwsp.edu. Retrieved 2013-06-03.
  12. ↑ Ma, B; Li, M; Nong, H; Shi, J; Liu, G; Zhang, J (2008). "Protective effects of extract of Coeloglossum viride var. Bracteatum on ischemia-induced neuronal death and cognitive impairment in rats". Behavioural Pharmacology. 19 (4): 325–33. doi:10.1097/FBP.0b013e3282feb0ac. PMC 2910418. PMID 18622180.
  13. ↑ Zhang, D; Zhang, J. J. (2005). "Effect of Coeloglossum. Viride var. Bracteatum extract on oxidation injury in sub-acute senescent model mice". Acta Academiae Medicinae Sinicae. 27 (6): 729–33. PMID 16447647.
  14. ↑ Huang, Sheng-Yang; Li, Guo-Qiang; Shi, Jian-Gong; Mo, Shun-Yan; Wang, Su-Juan; Yang, Yong-Chun (2004). "Chemical constituents of the rhizomes of Coeloglossum viridevar.bracteatum". Journal of Asian Natural Products Research. 6 (1): 49–61. doi:10.1080/1028602031000119826. PMID 14989381.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.