Ephedra (plant)

Source: Wikipedia, the free encyclopedia.
(Redirected from
Ephedra (genus)
)
This article is about the genus Ephedra, and the family Ephedraceae. For the use of the plant as a medicine, see Ephedra (medicine).

Ephedra
Temporal range: Aptian–Recent
Ephedra viridis
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnospermae
Division: Gnetophyta
Class: Gnetopsida
Order: Ephedrales
Family: Ephedraceae
Genus: Ephedra
L.[1]
Type species
Ephedra distachya
Map showing the range of Ephedra
Global range of Ephedra
Synonyms[2]
  • Alloephedra Tao JR et Yang Y., 2003.
  • Chaetocladus Nelson 1866 nom. illeg.
  • Liaoxia Cao et S.Q. Wu, 1996

Ephedra is a genus of gymnosperm shrubs. The various species of Ephedra are widespread in many arid regions of the world, ranging across southwestern North America, southern Europe, northern Africa, southwest and central Asia, northern China and western South America.[2] It is the only extant genus in its family, Ephedraceae, and order, Ephedrales, and one of the three living members of the division Gnetophyta alongside Gnetum and Welwitschia.

In

temperate climates, most Ephedra species grow on shores or in sandy soils with direct sun exposure. Common names in English include joint-pine, jointfir, Mormon-tea or Brigham tea. The Chinese name for Ephedra species is mahuang (simplified Chinese: 麻黄; traditional Chinese: 麻黃; pinyin: máhuáng; Wade–Giles: ma-huang; lit. 'hemp yellow'). Ephedra is the origin of the name of the stimulant ephedrine
, which the plants contain in significant concentration.

Ephedra fragilis pollen cones
Ephedra distachya: ripe female cones with seeds
Ephedra ciliata seed

Description

The family

gymnosperms, and generally shrubs, sometimes clambering vines, and rarely, small trees. Members of the genus frequently spread by the use of rhizomes.[3]

The stems are green and photosynthetic.[4] The leaves are opposite or whorled. The scalelike leaves fuse into a sheath at the base and this often sheds soon after development. There are no resin canals.[3]

The plants are mostly dioecious, with the pollen strobili in whorls of 1–10, each consisting of a series of decussate[5] bracts. The pollen is furrowed. The female strobili also occur in whorls, with bracts which fuse around a single ovule. Fleshy bracts are white (such as in Ephedra frustillata) or red. There are generally 1–2 yellow to dark brown seeds per strobilus.[3]

Taxonomy

The genus Ephedra was first described in 1753 by

Dumortier.[6][9]

Evolutionary history

The oldest known members of the genus are from the Early Cretaceous around 125 million years ago, with records being known from the Aptian-Albian of Argentina,[10] China,[11] Portugal and the United States.[12] The fossil record of Ephedra outside of pollen disappears after the Early Cretaceous.[13] Molecular clock estimates have suggested that last common ancestor of living Ephedra species lived much more recently, during the Early Oligocene around 30 million years ago.[14] However, pollen modified from the ancestral condition of the genus with branched pseudosulci (grooves), which evolved in parallel in the living North American and Asian lineages is known from the Late Cretaceous, suggesting that the last common ancestor is at least this old.[13]

Species

Phylogeny of Ephedra[15][16]

As of June 2021, Plants of the World Online accepted the following species:[17]

Distribution

The genus is found worldwide, in desert regions, but not in Australia.[3]

Ecology

Karvachar

Ephedraceae are adapted to extremely arid regions, growing often in high sunny habitats, and occur as high as 4000 m above sea level in both the Andes and the Himalayas.[3] They make up a significant part of the North American Great Basin sage brush ecosystem.

Drug and supplement uses

Main article: Ephedra (medicine)
crude medicine
)

The Ephedra

spinal anesthesia.[19]

In the United States, ephedra supplements were banned from the market in the early 21st century due to serious safety risks.

respiratory infections, but there is no scientific evidence they are effective or safe for these purposes.[20]

Ephedra has also had a role as a precursor in the clandestine manufacture of methamphetamine.[21]

Adverse effects

Alkaloids obtained from the species of Ephedra used in herbal medicines, which are used to synthetically prepare pseudoephedrine and ephedrine, can cause cardiovascular events.[19] These events have been associated with arrhythmias, palpitations, tachycardia and myocardial infarction.[19] Caffeine consumption in combination with ephedrine has been reported to increase the risk of these cardiovascular events.[19][20]

Economic botany and alkaloid content

The earliest uses of Ephedra species (mahuang) for specific illnesses date back to 5000 BC.

HPLC analyses in industrial settings, the concentrations of total alkaloids in dried Herba Ephedra ranged between 1 and 4%, and in some cases up to 6%.[22]

For a review of the alkaloid distribution in different species of the genus Ephedra see Jian-fang Cui (1991).[23] Other American and European species of Ephedra, e.g. Ephedra nevadensis (Nevada Mormon tea) have not been systematically assayed; based on unpublished field investigations, they contain very low levels (less than 0.1%) or none at all.[24]

See also

References

  1. ISBN 3540517944
    .
  2. ^ a b Kew World Checklist of Selected Plant Families
  3. ^ a b c d e Judd WS, Campbell CS, Kellog EA, Stevens PF, Donoghue MJ (2007). Plant Systematics, a phylogenetic approach (3rd. ed.). Sinauer associates, Inc.
  4. ^ "Family "Ephedraceae"". Angiosperm Phylogeny Website. Retrieved 5 July 2019.
  5. ^ Messina A (2014). "VicFlora: Ephedraceae". Victoria, Australia: Royal Botanic Gardens Foundation. Retrieved 5 July 2019.
  6. ^ a b The Gymnosperm database: Ephedra. Retrieved 5 July 2019.
  7. ^ a b Linnaeus C (1753). Species Plantarum. Vol. 2. p. 1040.
  8. ^ Linnaeus C (1754). Genera plantarum. Vol. 5. p. 462.
  9. ^ Dumortier BC (1829). Analyse des familles des plantes, avec l'indication des principaux genres qui s'y rattachent. Tournay: J. Casterman aîné. p. 11.
  10. S2CID 23766815
    .
  11. PMID 23341964
    .
  12. PMID 16675607
    .
  13. ^
    S2CID 83696018
    .
  14. ISSN 1759-6831
    .
  15. S2CID 232282918
    .
  16. doi:10.6084/m9.figshare.14547354.v1. {{cite journal}}: Cite journal requires |journal= (help
    )
  17. ^ "Ephedra Tourn. ex L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 23 June 2021.
  18. doi:10.3329/bjpt.v23i2.30850
    .
  19. ^ a b c d e "Ephedrine". Drugs.com. 9 January 2021. Retrieved 23 June 2021.
  20. ^ a b c d "Ephedra". National Center for Complementary and Integrative Health, US National Institutes of Health. 1 July 2020. Retrieved 23 June 2021.
  21. ^ "Ephedra's Role As a Precursor in the Clandestine Manufacture of Methamphetamine". Journal of Forensic Sciences 40(4), 551-560 (1995). Retrieved 30 December 2021.
  22. ISBN 0-12-469535-3
    .
  23. PMID 15635242
    .
  24. PMID 15084081
    .

External links

Wikimedia Commons has media related to Ephedra.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Ephedra_(plant)&oldid=1217617956"