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Toxicodendron vernicifluum

  (Redirected from Urushi)

Toxicodendron vernicifluum (formerly Rhus verniciflua[1]), also known by the common name Chinese lacquer tree,[1][2][3] is an Asian tree species of genus Toxicodendron (formerly Rhus) native to China and the Indian subcontinent, and cultivated in regions of China, Korea and Japan.[4] Other common names include Japanese lacquer tree,[5] Japanese sumac,[4] and varnish tree.[5] The trees are cultivated and tapped for their toxic sap, which is used as a highly durable lacquer to make Chinese, Japanese, and Korean lacquerware.

Toxicodendron vernicifluum
Toxicodendron vernicifluum 01.jpg
Scientific classification edit
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Sapindales
Family: Anacardiaceae
Genus: Toxicodendron
Species:
T. vernicifluum
Binomial name
Toxicodendron vernicifluum
(Stokes) F. Barkley
Fruits of T. vernicifluum

The trees grow up to 20 metres tall with large leaves, each containing from 7 to 19 leaflets (most often 11–13). The sap contains the allergenic compound urushiol, which gets its name from this species' Japanese name urushi (urushi ()); "urushi" is also used in English as a collective term for all kinds of Asian lacquerware made from the sap of this and related Asian tree species, as opposed to European "lacquer" or Japanning made from other materials. Urushiol is the oil found in poison ivy that causes a rash.

Contents

UsesEdit

A caustic, toxic sap, containing urushiol, is tapped from the trunk of the Chinese lacquer tree to produce lacquer. This is done by cutting 5 to 10 horizontal lines on the trunk of a 10-year-old tree, and then collecting the greyish yellow sap that exudes. The sap is then filtered, heat-treated, or coloured before applying onto a base material that is to be lacquered. Curing the applied sap requires "drying" it in a warm, humid chamber or closet for 12 to 24 hours where the urushiol polymerizes to form a clear, hard, and waterproof surface. In its liquid state, urushiol can cause extreme rashes, even from vapours. Once hardened, reactions are possible but less common.

Products coated with lacquer are recognizable by an extremely durable and glossy finish. Lacquer has many uses; some common applications include tableware, musical instruments, fountain pens,[6] jewelry, and bows. There are various types of lacquerware. The cinnabar-red is highly regarded. Unpigmented lacquer is dark brown but the most common colors of urushiol finishes are black and red, from powdered iron oxide pigments of ferrous-ferric oxide (magnetite) and ferric oxide (rust), respectively. Lacquer is painted on with a brush and is cured in a warm and humid environment.

Artistic application and decoration of lacquer can be a long process, requiring many hours or days of careful and repetitive layers and drying times. The creation of a single piece of urushi art, such as a bowl or a fountain pen, may take weeks to months to complete. Lacquer is a very strong adhesive.

The leaves, seeds, and the resin of the Chinese lacquer tree are sometimes used in Chinese medicine for the treatment of internal parasites and for stopping bleeding. Compounds butein and sulfuretin are antioxidants, and have inhibitory effects on aldose reductase and advanced glycation processes.[7]

Buddhist monks who practiced the art of Sokushinbutsu would use the tree's sap in their ceremony.

See alsoEdit

ReferencesEdit

  1. ^ a b "PLANTS Profile for Toxicodendron vernicifluum (Chinese lacquer)". Natural Resources Conservation Service. United States Department of Agriculture. Retrieved 8 August 2011.
  2. ^ Yun-Yang, W.; Yu-Min, D.; Fang-Xing, Y.; Ying, X.; Rong-Zhi, C.; Kennedy, J. F. (2006). "Purification and characterization of hydrosoluble components from the sap of Chinese lacquer tree Rhus vernicifera". International Journal of Biological Macromolecules. 38 (3–5): 232–40. doi:10.1016/j.ijbiomac.2006.02.019. PMID 16580725.
  3. ^ Mabberley, D. J. (2002). The plant-book: A portable dictionary of the vascular plants (2nd ed.). Cambridge, U.K.: Cambridge University Press. p. 286. ISBN 978-0-521-41421-0.
  4. ^ a b "Toxicodendron vernicifluum". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 10 December 2013.
  5. ^ a b "Common Names for Chinese Lacquer (Toxicodendron vernicifluum)". Encyclopedia of Life. Retrieved 10 December 2013.
  6. ^ Fountain Pens made with Urushi lacquer Archived 16 March 2015 at the Wayback Machine.
  7. ^ Lee, E. H.; Song, D. G.; Lee, J. Y.; Pan, C. H.; Um, B. H.; Jung, S. H. (August 2008). "Inhibitory effect of the compounds isolated from Rhus verniciflua on aldose reductase and advanced glycation endproducts". Biological and Pharmaceutical Bulletin. 31 (8): 1626–30. doi:10.1248/bpb.31.1626. PMID 18670102.

Further readingEdit

  • Duke, James A.; Ayensu, Edward S. Medicinal Plants of China. Algonac, Mich.: Reference Publications, Inc. 1985. ISBN 0-917256-20-4.
  • Kim, Ki Hyun; Moon, Eunjung; Choi, Sang Un; Pang, Changhyun; Kim, Sun Yeou; Lee, Kang Ro (13 March 2015). "Identification of cytotoxic and anti-inflammatory constituents from the bark of Toxicodendron vernicifluum (Stokes) F.A. Barkley". Journal of Ethnopharmacology. 162: 231–237. doi:10.1016/j.jep.2014.12.071.
  • Stutler, Russ. "A Little more information on Urushi". December 2002.
  • Suganuma, Michiko. "Japanese lacquer".

External linksEdit