Uncaria is a genus of flowering plants in the family Rubiaceae. It has about 40 species.[1] Their distribution is pantropical, with most species native to tropical Asia, three from Africa and the Mediterranean and two from the neotropics.[2] They are known colloquially as gambier, cat's claw or uña de gato. The latter two names are shared with several other plants. The type species for the genus is Uncaria guianensis.[3]

Uncaria
Uncaria gambir
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Gentianales
Family: Rubiaceae
Subfamily: Cinchonoideae
Tribe: Naucleeae
Genus: Uncaria
Schreber
Type species
Uncaria guianensis
Species

~40 species. See text

Indonesian Gambier (U. gambir) is a large tropical vine with leaves typical of the genus, being opposite and about 10 cm (3.9 in) long. The South American U. tomentosa is called Uña de Gato. Uncaria sinensis is common in China.

Uncaria was named in 1789 by Johann von Schreber in his Genera Plantarum edition 8[a] (not to be confused with books of the same title by Linnaeus, Jussieu, and others).[4][5] The genus name is derived from the Latin word uncus, meaning "a hook".[6] It refers to the hooks, formed from reduced branches, that Uncaria vines use to cling to other vegetation.

Uncaria is a member of the tribe Naucleeae, but its position within that tribe remains unresolved.[7]

Description

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Woody lianas; climbing by hooks formed from reduced, modified branches. Stipules entire or bifid. Inflorescences are compact heads at the ends of horizontal, very reduced branches. Corolla lobes without appendages. Seeds with a long wing at each end, the lower wing deeply bifid.[8]

Species

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U. hirsuta

As of March 2023, Plants of the World Online accepted the following species:[9]

Uses

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Diplomat Edmund Roberts noted that, upon his visit to China in the 1830s, Chinese were using U. gambir for tanning, and noted that the U. gambir made "leather porous and rotten." He also noted that Chinese would chew it with areca nut.[10] The plant extract contains some 150 identified phytochemicals, including catechins, proanthocyanins, and chalcone-flavan-3-ol dimers, called gambiriins.[11][12] Cat's claw (U. tomentosa) and the Chinese Uncaria species are used in traditional medicine, although there is no high-quality clinical evidence they have any medicinal properties.[11]

Adverse effects

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Although cat's claw appears to be safe for human use below 350 milligrams per day over 6 weeks, its adverse effects may include nausea, diarrhea, upset stomach, and an increased risk of bleeding if used with an anticoagulant drug.[11]

References

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  1. ^ Uncaria At: World Checklist of Rubiaceae At: Kew Gardens Website. (see External links below).
  2. ^ David J. Mabberley. 2008. Mabberley's Plant-Book third edition (2008). Cambridge University Press: UK. ISBN 978-0-521-82071-4
  3. ^ Uncaria In: Index Nominum Genericorum. In: Regnum Vegetabile (see External links below).
  4. ^ Uncaria in International Plant Names Index. (see External links below).
  5. ^ Johann Schreber. 1789. Gen. Pl., ed. 8[a]. (Genera Plantarum Eorumque Characteres Naturales Secundum Numerum, Figuram, Situm, & Proportionem Omnium Fructificationis Partium. (Ed. 8[a])). volume 1, page 125. Frankfurt am Main, Germany(see External links below).
  6. ^ Umberto Quattrocchi. 2000. CRC World Dictionary of Plant Names volume IV. CRC Press: Boca Raton; New York; Washington, DC;, USA. London, UK. ISBN 978-0-8493-2673-8 (set).
  7. ^ Manns, Ulrika; Bremer, Birgitta (2010). "Towards a better understanding of intertribal relationships and stable tribal delimitations within Cinchonoideae s.s. (Rubiaceae)"". Molecular Phylogenetics and Evolution. 56 (1): 21–39. doi:10.1016/j.ympev.2010.04.002. PMID 20382247.
  8. ^ Ridsdale, Colin E. (1978). "A revision of Mitragyna and Uncaria (Rubiaceae)"". Blumea. 24 (1): 43–100.
  9. ^ "Uncaria Schreb." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2023-03-20.
  10. ^ Roberts, Edmund (1837). Embassy to the Eastern Courts of Cochin-China, Siam, and Muscat. New York: Harper & Brothers. p. 138.
  11. ^ a b c "Cat's claw". Drugs.com. 13 August 2018. Retrieved 23 September 2018.
  12. ^ Taniguchi, S.; Kuroda, K.; Doi, K.; Tanabe, M.; Shibata, T.; Yoshida, T.; Hatano, T. (2007). "Revised structures of gambiriins A1, A2, B1, and B2, chalcane-flavan dimers from gambir (Uncaria gambir extract)". Chemical & Pharmaceutical Bulletin. 55 (2): 268–72. doi:10.1248/cpb.55.268. PMID 17268100.
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