Echinacea

Source: Wikipedia, the free encyclopedia.
This article is about the flowering plant. For the sea urchins, see Echinacea (animal).

Echinacea
Echinacea purpurea 'Maxima'
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Subfamily: Asteroideae
Tribe: Heliantheae
Subtribe: Zinniinae
Genus: Echinacea
Moench, 1794
Synonyms

Brauneria Necker ex T.C.Porter & Britton
Helichroa

Raf.

Echinacea

heads of composite flowers, blooming in summer. The generic name is derived from the Greek word ἐχῖνος (ekhinos), meaning "hedgehog", due to the spiny central disk. These flowering plants and their parts have different uses. Some species are cultivated in gardens for their showy flowers. Two of the species, E. tennesseensis and E. laevigata, were formerly listed in the United States as endangered species; E. tennesseensis has been delisted due to recovery[1] and E. laevigata is now listed as threatened.[2]

Echinacea purpurea is used in traditional medicine. Although commonly sold as a dietary supplement, there is insufficient scientific evidence that Echinacea products are effective or safe for improving health or treating any disease.

Description

The spiny center of the head showing the paleae, from which the name derives
A bee on an Echinacea paradoxa head (inflorescence)
A bee on an Echinacea purpurea head
Fasciation on an Echinacea purpurea

Echinacea species are

dentate or serrate
.

The flowers are collected together into single rounded

pappi are persistent and variously crown-shaped with 0 to 4 or more prominent teeth. x = 11.[3]

Like all

flower head
opens, thus forming a cone. Plants are generally long lived, with distinctive flowers. The common name "coneflower" comes from the characteristic center "cone" at the center of the flower head.

Taxonomy

The first Echinacea species were discovered by European explorers in forests of southeastern North America during the 18th century.

De Candolle elevated this variety to a species in its own right, as Echinacea serotina (Nutt.) DC, by which time four species of the genus Echinacea were recognised.[11][4]

Historically, there has been much confusion over the taxonomic treatment of the genus, largely due to the ease with which the taxa

type specimen for Echinacea purpurea (L) Moench was not the one originally described by Linnaeus, but rather that described by De Candolle as Echinacea serotina (Nutt.) DC.[4]

Subdivision

Many taxonomic treatments of the genus Echinacea have recorded varying numbers of subordinate

taxa, ranging between 2 and 11.[4] One of the most widely adopted schemes was that of McGregor (1968),[12] which included nine species, of which two, E. angustifolia DC and E. paradoxa (Norton) Britton, were further divided into two varietals.[8] Treatments that include ten species, differ by the addition of E. serotina (Nutt.) DC.[14] Alternative classification include with four species and eight subspecies, and two subgenera with four species, has been proposed, based on morphology alone, but has proved controversial.[13] This recognised subgenus Echinacea, with the single species E. purpurea, and subgenus Pallida, with three species, E. atrorubens, E. laevigata and E. pallida. In this scheme, other taxa are reduced to variety rank, e.g. E. atrorubens var. neglecta.[6][15] Subsequently, McGregor's classification was preserved in the Flora of North America (2006).[3]

DNA analysis has been applied to determine the number of Echinacea species, allowing clear distinctions among species based on chemical differences in root metabolites. The research concluded that of the 40 genetically diverse populations of Echinacea studied, there were nine to ten distinct species.[16]

Species

Plants of the World Online gives nine accepted species,[17] and World Flora Online gives ten:[18]

These two databases differ in their treatment of E. serotina (Nutt.) DC. , the former considering this as a synonym of E. purpurea and the latter as a distinct species.

Former classification

Etymology

Moench named the genus Echinacea, from the Greek word

sea-urchin, in recognition that in the seed stage, the cone has spiny projections.[8][19]

Distribution and habitat

Echinacea is restricted to North America, east of the Rocky Mountains, and in the Atlantic drainage area, predominantly the Great Plains and central United States and adjacent areas of Canada.[15][4][20] The genus range is from Saskatchewan in the north to almost the Gulf of Mexico in Louisiana and Texas in the south, and from the Ohio oak savannas, glades of Tennessee and the Carolinas in the east, to the Rocky Mountain foothills in the west.[14]

Conservation

Natural populations of Echinacea are threatened by over-harvesting of wild specimens for the herbal product trade and modification of their habitats by humans.[20] Major reductions in the size of populations of E. laevigata and E. tennesseensis have led to their classification as endangered species.[15][21] E. tennesseensis had recovered sufficiently by 2011 that it was removed from the list.[22]

Cultivation

Many species of Echinacea are cultivated for commercial use,[15] while others, notably E. purpurea, E. angustifolia, and E. pallida, are grown as ornamental plants in gardens.[23] Many cultivars exist, and many of them are asexually propagated to keep them true to type.

Uses

Echinacea has long been used as a traditional medicine.[15]

History

colds, influenza and sepsis. Despite many different preparations and hundreds of publications, no exact identification of a truly active ingredient has been identified.[24]

Infectious diseases

Echinacea is of no benefit as a treatment for the common cold.

respiratory infections.[29]

Side effects

When taken by mouth, Echinacea does not usually cause

leucopenia, hepatitis, kidney failure, and atrial fibrillation, although it is not clear that these were due to Echinacea itself.[31] Up to 58 drugs or supplements may interact with Echinacea.[32]

As a matter of manufacturing safety, one investigation by an independent-consumer testing laboratory found that five of eleven selected retail Echinacea products failed quality testing. Four of the failing products contained levels of phenols below the potency level stated on the labels. One failing product was contaminated with lead.[37]

Children under 12 years old

The European Herbal Medicinal Products Committee (HMPC) and the UK Herbal Medicines Advisory Committee (HMAC) recommended against the use of Echinacea-containing products in children under the age of 12. Manufacturers re-labelled all oral Echinacea products that had product licenses for children with a warning that they should not be given to children under 12 as a precautionary measure.[38]

Pregnancy

Although research has not found increased risk of

pregnant women should avoid Echinacea products until stronger safety supporting evidence becomes available.[31]

Lactation

It is recommended that women breastfeeding should use caution with Echinacea products due to insufficient safety information available.[31]

General precaution

The U.S.

over-the-counter medicines.[39]

As with any herbal preparation, individual doses of Echinacea may vary significantly in chemical composition.

adulteration with other products, leading to potential for substantial product variability.[28][37]

Research

Echinacea products vary widely in composition.

extracts and expressed juice), and different chemical compositions which complicate understanding of a potential effect.[41][42]
Well-controlled clinical trials[43] are limited and low in quality, with little scientific evidence that Echinacea supplement products are useful for treating any disease.[32][42][28]

According to

radiotherapy, but this has not been proven either."[44]

Although there are multiple

scientific reviews and meta-analyses[45] published on the supposed immunological effects of Echinacea, there is significant variability of products used among studies, leading to low-quality or no evidence for efficacy and safety, leading to considerable controversy.[27] Consequently, regulatory authorities, such as the United States Food and Drug Administration, have not approved Echinacea products as safe and effective for any health or therapeutic purpose.[30][32][42]

See also

  • List of ineffective cancer treatments

References

  1. ^ "Tennessee purple coneflower (Echinacea tennesseensis)". Environmental Conservation Online System. U.S. Fish & Wildlife Service. Retrieved 19 June 2023.
  2. ^ "Smooth coneflower (Echinacea laevigata)". Environmental Conservation Online System. U.S. Fish & Wildlife Service. Retrieved 19 June 2023.
  3. ^ a b Urbatsch et al 2006.
  4. ^ a b c d e Binns et al 2004.
  5. ^ Linnaeus 1753.
  6. ^ a b Binns et al 2001.
  7. ^ Moench 1794.
  8. ^ a b c Kindscher & Wittenberg 2006, p. 9.
  9. ^ Tropicos 2021.
  10. ^ Nuttall 1818, p. 2:178.
  11. ^ de Candolle 1824–1873, p. 5: 554.
  12. ^ a b McGregor 1968.
  13. ^ a b c Kindscher & Wittenberg 2016, p. 38.
  14. ^ a b Flagel et al 2008.
  15. ^ a b c d e Binns et al 2002.
  16. ^ Perry 2010.
  17. ^ POWO 2021.
  18. ^ WFO 2021.
  19. ^ Plowden 1972, p. 7.
  20. ^ a b Kindscher 2021.
  21. ^ Kindscher 2006.
  22. ^ Fish and Wildlife Service 2011.
  23. ^ McCoy et al 2005.
  24. ^ a b Hostettmann 2003.
  25. ^ Kindscher 2007, p. 156.
  26. ^ Moerman 1998, p. 205.
  27. ^ a b Chang 2007.
  28. ^ a b c Karsch-Volk et al 2014.
  29. ^ Schapowal et al 2015.
  30. ^ a b c NCCIH 2020.
  31. ^ a b c d e Natural Standard Research Collaboration 2013.
  32. ^ a b c d e Drugsite 2021.
  33. ^ Izzo & Ernst 2009.
  34. ^ a b c Huntley et al 2005.
  35. ^ Mullins 1998.
  36. ^ Ang-Lee et al 2001.
  37. ^ a b Cooperman 2021.
  38. ^ MHRA 2014.
  39. ^ FDA 2017.
  40. ^ NCCIH 2020a.
  41. ^ Barnes et al 2005.
  42. ^ a b c Hart & Dey 2009.
  43. ^ Turner et al 2005.
  44. ^ Cancer Research UK 2019.
  45. ^ Shah et al 2007.

Bibliography

Books and documents

Historical sources

Chapters

Articles
Taxonomy and phylogeny
Traditional medicine

Websites
Databases and floras

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Echinacea&oldid=1219160135"