Larrea tridentata

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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

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

In the book The Land of Little Rain the author Mary Hunter Austin wrote that the desert of the Death Valley "begins with the creosote."
In the classic science fiction series Dune by Frank Herbert, the Fremen inhabitants of the planet Arrakis rub the juices of the creosote bush into the palms of their hands to prevent water loss through the skin.
King Creosote, is a nickname of an independent singer-songwriter from Fife, Scotland.
In the 2005 film Kingdom of Heaven, Orlando Bloom's character Balian utters the line "A spark and a creosote bush, there is your Moses, there is your religion", suggesting that the burning bush in the Bible was a simple creosote bush being sparked by a thrown rock.

References

↑ "Taxon: Larrea tridentata (DC.) Coville". Taxonomy for Plants. USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN).
↑ 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.
↑ 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.
↑ "Larrea tridentata". The Jepson Manual. Berkeley, CA: University of California. Retrieved 2011-12-30.
↑ "Larrea tridentata (Sesse' and Moc. ex DC.) Coville - Creosote Bush" (PDF). US Forest Service.
↑ 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.
↑ 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.
↑ Tilford, G. L. Edible and Medicinal Plants of the West. Missoula, MT: Mountain Press Publishing. ISBN 0-87842-359-1.
↑ "Health Canada warns consumers not to take products containing chaparral". Health Canada. 21. December 2005. Check date values in: |date= (help)

External links

"Creosote Bush". US National Park Service.
"Larrea tridentata". Jepson Flora Project. Berkeley, CA: University of California.
"Larrea tridentata". Dr. Duke's Phytochemical and Ethnobotanical Databases. Germplasm Resources Information Network - GRIN.
"Larrea tridentata". Fire Effect Information System. US Forest Service.
"King Clone, The World's Oldest Living Thing". Botanical Record-Breakers. Waynesworld.

photo links

"Creosote bush in desert landscape". EPA.
"Larrea tridentata Photos". Suu.edu.
"Larrea tridentata". CalPhotos. Berkeley, CA: University of California.
"Creosote Bush – Pictures and Information". Blackturtle.

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

[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.

[ucjeps-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.

[arteaga-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)

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