Rehmannia Explained

Rehmannia is a genus of seven species of flowering plants in the order Lamiales and family Orobanchaceae, endemic to China.[1] It has been placed as the only member of the monotypic tribe Rehmannieae,[2] [3] but molecular phylogenetic studies suggest that it forms a clade with Triaenophora. Contrary to the immense majority of the taxa of Orobanchaceae, Rehmannia is not parasitic.

Systematics

Etymology

Rehmannia is named for Joseph Rehmann (1788–1831), a physician in St. Petersburg.[4]

Homonymy

The name "Rehmannia" has also been given to a genus of Jurassic ammonites of the family Reineckeidae.

Classification

The genus was included in the family Scrophulariaceae or Gesneriaceae in some older classifications. The current placement of the genus is in neither Scrophulariaceae s.s. nor Plantaginaceae s.l. (to which many other former Scrophulariaceae have been transferred). Earlier molecular studies suggested that its closest relatives were the genera Lancea and Mazus,[5] which have been included in Phrymaceae.[6] Subsequently, it was found that Rehmannia groups with Triaenophora, and both taxa are jointly the sister group to Lindenbergia and the parasitic Orobanchaceae.[7] A 2016 classification of flowering plants, the APG IV system enlarged Orobanchaceae to include Rehmannia,[8] making it one of the few genera in the family, along with Lindenbergia, not to be parasitic.

Species list

, Plants of the World Online accepted six species:[9]

Image Scientific Name Distribution
Rehmannia chingii H.L.LiChina
Rehmannia chrysantha M.H.Li & C.H.ZhangInner Mongolia
Rehmannia glutinosa (Gaertn.) DC.China
Rehmannia henryi N.E.Br.China (Hubei)
Rehmannia japonica (Thunb.) MakinoJapan (C. Honshu).
Rehmannia piasezkii Maxim.China (Hubei, Shanxi)
Rehmannia solanifolia P.C.Tsoong & T.L.ChinChina (Sichuan)

Uses

Sometimes known as Chinese foxglove due to its superficial resemblance to the genus Digitalis, the species of Rehmannia are perennial herbs. The plants have large flowers and are grown as ornamental garden plants in Europe and North America, and are used medicinally in Asia.

Traditional Chinese medicine

Known as dìhuáng (黄) or gān dìhuáng (干地黄) in Chinese, R. glutinosa is used as a medicinal herb for many conditions within Chinese traditional formulations.[10]

It is the main ingredient in a mixture called si wu tang (four substance decoction) along with Dang gui, Chinese peony (bai shao yao), and Ligusticum striatum (chuan xiong) that is considered a fundamental medicine to support making blood.[11]

When two ingredients, peach (tao ren) and safflower (hong hua), are added, it is called tao hong si wu tang (four substance decoction with peach pit and safflower), which is used in TCM for fatigue.[11]

Chemical constituents

Rehmannia contains the vitamins A, B, C, and D, as well as other compounds, such as catalpol, an iridoid glycoside.

Notes and References

  1. Web site: Rehmannia in Flora of China @ efloras.org . www.efloras.org . 2020-05-10 .
  2. Rouy . G. . 1909 . Conspectus des tribus et des genres de la famille des Scrofulariacées . Rev. Gen. Bot. . 21 . 194–207 .
  3. Book: Kadereit, Joachim W. . Flowering Plants · Dicotyledons: Lamiales (except Acanthaceae including Avicenniaceae) . 2012-12-06 . 426 . Springer Science & Business Media . 978-3-642-18617-2 . en .
  4. Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 328
  5. Oxelman . Bengt . Kornhall . Per . Olmstead . Richard G. . Bremer . Birgitta . 2005 . Further disintegration of Scrophulariaceae . Taxon . en . 54 . 2 . 411–425 . 10.2307/25065369 . 25065369 . 1996-8175.
  6. Beardsley . Paul M. . Olmstead . Richard G. . 2002 . Redefining Phrymaceae: the placement of Mimulus, tribe Mimuleae, and Phryma . American Journal of Botany . en . 89 . 7 . 1093–1102 . 10.3732/ajb.89.7.1093 . 21665709 . 1537-2197.
  7. Xia . Zhi . Wang . Yin-Zheng . Smith . James F. . 2009 . Familial placement and relations of Rehmannia and Triaenophora (Scrophulariaceae s.l.) inferred from five gene regions . American Journal of Botany . en . 96 . 2 . 519–530 . 10.3732/ajb.0800195 . 21628207 . 1537-2197.
  8. The Angiosperm Phylogeny Group . An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV . Botanical Journal of the Linnean Society . January 2016 . 181 . 1–20 . 10.1111/boj.12385 . free .
  9. Web site: Rehmannia Libosch. ex Fisch. & C.A.Mey. . Plants of the World Online . Royal Botanic Gardens, Kew. 2022-03-21.
  10. Jim English. 2010. Traditional Chinese Herbs for Arthritis. Nutrition Review. 5. 2. 2011-12-29. dead. https://web.archive.org/web/20111210175401/http://www.nutritionreview.org/library/arthritissupport.php. 2011-12-10.
  11. Book: Liu . Chongyun . Tseng . Angela . Yang . Sue . Chinese Herbal Medicine: Modern Applications of Traditional Formulas . 2004 . CRC Press . 9780203493892 . 174–175 . en.