Larrea tridentata

Revision as of 16:33, 30 October 2012 by Prashanthsaddala (talk | contribs)
Jump to navigation Jump to search
style="background:#Template:Taxobox colour;"|Template:Taxobox name
Larrea tridentata at Furnace Creek, Death Valley, California.
Larrea tridentata at Furnace Creek, Death Valley, California.
style="background:#Template:Taxobox colour;" | Scientific classification
Kingdom: Plantae
(unranked) Eudicots
(unranked) Rosids
Order: Zygophyllales
Family: Zygophyllaceae
Genus: Larrea
Species: L. tridentata
Binomial name
Larrea tridentata
(DC.) Coville[1]

WikiDoc Resources for Larrea tridentata

Articles

Most recent articles on Larrea tridentata

Most cited articles on Larrea tridentata

Review articles on Larrea tridentata

Articles on Larrea tridentata in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Larrea tridentata

Images of Larrea tridentata

Photos of Larrea tridentata

Podcasts & MP3s on Larrea tridentata

Videos on Larrea tridentata

Evidence Based Medicine

Cochrane Collaboration on Larrea tridentata

Bandolier on Larrea tridentata

TRIP on Larrea tridentata

Clinical Trials

Ongoing Trials on Larrea tridentata at Clinical Trials.gov

Trial results on Larrea tridentata

Clinical Trials on Larrea tridentata at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Larrea tridentata

NICE Guidance on Larrea tridentata

NHS PRODIGY Guidance

FDA on Larrea tridentata

CDC on Larrea tridentata

Books

Books on Larrea tridentata

News

Larrea tridentata in the news

Be alerted to news on Larrea tridentata

News trends on Larrea tridentata

Commentary

Blogs on Larrea tridentata

Definitions

Definitions of Larrea tridentata

Patient Resources / Community

Patient resources on Larrea tridentata

Discussion groups on Larrea tridentata

Patient Handouts on Larrea tridentata

Directions to Hospitals Treating Larrea tridentata

Risk calculators and risk factors for Larrea tridentata

Healthcare Provider Resources

Symptoms of Larrea tridentata

Causes & Risk Factors for Larrea tridentata

Diagnostic studies for Larrea tridentata

Treatment of Larrea tridentata

Continuing Medical Education (CME)

CME Programs on Larrea tridentata

International

Larrea tridentata en Espanol

Larrea tridentata en Francais

Business

Larrea tridentata in the Marketplace

Patents on Larrea tridentata

Experimental / Informatics

List of terms related to Larrea tridentata

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Larrea tridentata is known as Creosote bush as a plant, chaparral as a medicinal herb,[2] and as "gobernadora" in Mexico, Spanish for "governess," due to its ability to secure more water by inhibiting the growth of nearby plants. In Sonora, it is more commonly called "hediondilla." [3]

It is a flowering plant in the family Zygophyllaceae. The species is named after Juan Antonio Hernandez de Larrea, a Spanish clergyman.[4]

Habitat

Creosote bush is most common on the well-drained soils of alluvial fans and flats. In parts of its range, it may cover large areas in practically pure stands, though it usually occurs in association with Ambrosia dumosa (burro bush or bur-sage). Despite this common habitat, creosote bush roots have been found to produce chemicals that inhibit the growth of burro bush roots, and much of their relationship is currently unexplained. Such chemicals, however, have failed to explain the peculiar regularity in the spacing of individual plants within a stand.

Creosote bush stands tend to resemble man-made orchards in the even placement of plants. Originally, it was assumed that the plant produced some sort of water-soluble inhibitor that prevented the growth of other bushes near mature, healthy bushes. Now, however, it has been shown that the root systems of mature creosote plants are simply so efficient at absorbing water that fallen seeds nearby cannot accumulate enough water to germinate, effectively creating dead zones around every plant.[citation needed] It also seems that all plants within a stand grow at approximately the same rate, and that the creosote bush is a very long-living plant.

Desert adaptation

File:Creosote Larrea tridentata.JPG
A young Larrea tridentata plant

Contributing to the harshness of the germination environment above mature root systems, young creosote bushes are much more susceptible to drought stress than established plants. Germination is actually quite active during wet periods, but most of the young plants die very quickly unless there are optimal water conditions. Ground heat compounds the young plants' susceptibility to water stress, and ground temperatures can reach upwards of 70°C (160°F). To become established, it seems the young plant must experience a pattern of three to five years of abnormally cool and moist weather during and after germination. From this, it can be inferred that all the plants inside a stand are of equal age.

Mature plants, however, can tolerate extreme drought stress. In terms of negative water potential, creosote bushes can operate fully at -50 bars of water potential and have been found living down to -120 bars, although the practical average floor is around -70 bars, where the plant's need for cellular respiration generally exceeds the level that the water-requiring process of photosynthesis can provide. Cell division can occur during these times of water stress, and it is common for new cells to quickly absorb water after rainfall. This rapid uptake causes branches to 'grow' several centimeters at the end of a dry season.

Water loss is reduced by the resinous, waxy coating of the leaves, and by their small size which prevents them from heating up above air temperature (which would increase the vapor pressure deficit between the leaf and the air, and thus would increase water loss). Plants do drop some leaves heading into summer, but if all leaves are lost, the plant will not recover. Accumulation of fallen leaves, as well as other detritus caught from the passing wind, creates an ecological community specific to the creosote bush canopy, including beetles, millipedes, pocket mice, and kangaroo rats.

Uses

File:Larrea tridentata 3.jpg
A Larrea tridentata flower

Native American medicinals

Larrea tridentata was used by Native Americans in the Southwest as a treatment for many maladies, including sexually transmitted diseases, tuberculosis, chicken pox, dysmenorrhea, and snakebite.[5] The shrub is still widely used as a medicine in Mexico. It contains nordihydroguaiaretic acid.[6]

Herbal supplements and toxicity

Larrea tridentata is often referred to as chaparral when used as a herbal remedy and supplement; however, it does not grow in the synonymous plant community chaparral.[7] The United States Food and Drug Administration has issued warnings about the health hazards of ingesting chaparral or using it as an internal medicine, and discourages its use.[8] In 2005, Health Canada issued a warning to consumers to avoid using the leaves of Larrea species because of the risk of damage to the liver and kidneys.[9]

In literature and popular culture

See also

References

  1. "Taxon: Larrea tridentata (DC.) Coville". Taxonomy for Plants. USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN).
  2. Moore, M. (1989). Medicinal Plants of the Desert and Canyon West. Santa Fe, NM: Museum of New Mexico Press. pp. 27–32. ISBN 978-0-8901-3181-7.
  3. Felger, R. S.; Moser, M. B. (1985). People of the Desert and Sea - Ethnobotany of the Seri Indians. Tucson, AZ: University of Arizona Press. ISBN 978-0-8165-1267-6.
  4. "Larrea tridentata". The Jepson Manual. Berkeley, CA: University of California. Retrieved 2011-12-30.
  5. "Larrea tridentata (Sesse' and Moc. ex DC.) Coville - Creosote Bush" (PDF). US Forest Service.
  6. Arteaga, S.; Andrade-Cetto, A.; Cardenas, R. (2005). "Larrea tridentata (Creosote Bush), an abundant plant of Mexican and US-American deserts and its metabolite nordihydroguaiaretic acid". Journal of Ethnopharmacology. 98 (3): 231–239. doi:10.1016/j.jep.2005.02.002. PMID 15814253.
  7. Nabhan, G. P. (1993). Gathering the Desert. University of Arizona Press. p. 16. ISBN 978-0-8165-1014-6. ...health food stores have been marketing Larrea as a cure-all that they whimsically called "chaparral tea" – the plant never grows above the desert in true chaparral vegetation.
  8. Tilford, G. L. Edible and Medicinal Plants of the West. Missoula, MT: Mountain Press Publishing. ISBN 0-87842-359-1.
  9. "Health Canada warns consumers not to take products containing chaparral". Health Canada. 21. December 2005. Check date values in: |date= (help)

External links

photo links

ar:حشيشة الشحم ca:Arbust de creosota de:Kreosotbusch fa:بوته قطران it:Larrea tridentata nl:Creosootstruik fi:Kreosoottipensas uk:Креозотовий кущ