Salsola
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Salsola".

Salsola
Salsola oppositifolia
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Caryophyllales Family: Chenopodiaceae Subfamily: Salsoloideae Genus: Salsola L.
Species
About 100-130 species; see text.

Salsola (also known as Tumbleweed, Saltwort or Russian thistle) is a genus of herbs, subshrubs, shrubs and small trees in the family Chenopodiaceae, native to Africa, Asia, and Europe; they typically grow on flat, often dry and/or somewhat saline soils, with some species in saltmarshes.^[1] Recent genetic studies^[2] have however shown that the genus as traditionally circumscribed is paraphyletic, and many species are likely to be transferred to other genera in the future.

In several annual species, those known popularly as "tumbleweeds", the plants break away from their roots in the autumn, and are driven by the wind as a light, rolling mass, scattering seed far and wide. The seeds are produced in such large numbers that the plant has not developed protective coatings or food reserves for the coiled plant embryos. The deep, ineradicable taproot survives to grow again the following season. Contrary to popular belief, tumbleweeds are alive.

The genus Batis is also sometimes known as Saltwort but is unrelated to salsola.

Salsola as invasive species

A wind-blown tumbleweed caught against a fence

Several species, but most notably the central Asian S. tragus, are invasive outside their native range. They have become particularly abundant in parts of North America, where they are listed as noxious weeds by the U.S. Department of Agriculture. The salt-tolerant genus was first reported in the United States around 1877 in Bon Homme County, South Dakota, apparently transported as a stowaway in flax seed imported by Ukrainian farmers. South Dakota proved too harsh and dry for growing flax, but by 1900, Salsola had colonized as far west as the Pacific Coast. It was also actively introduced by the U.S.D.A., under the impression that cattle might be induced to eat it in hard times during droughts. Palatability of the young shoots is considered to be fair. Cattle, sheep, and horses will eat it, if nothing better is available. Small rodents and Pronghorn also graze on the young shoots. Tumbleweed thrives wherever land use has disturbed the soil. It can be seen in Death Valley, California, and in Colorado at elevations of 8500 feet (2600 meters).

Tumbleweed has naturalized to the point where it is regarded by many American people as native, changing the North American Great Plains plant community forever. It is controlled with mass applications of herbicides. Tumbleweeds are such a common symbol in Westerns, where it is used to indicate an abandoned area, that it is generally associated with the American Old West and Western films, despite its Ukrainian origin.

Salsola species are used as food plants by the larvae of some Lepidoptera species including The Nutmeg and the Coleophora case-bearers C. klimeschiella, C. parthenica, C. poeciliella (recorded on S. oppositifolia) and C. salsolella (feeds exclusively on S. vermiculata).

Salsola as food

The leaves and shoots of many species are edible, especially when young and tender, and some are grown as vegetables, often used for salads, sushi, or as a garnish. The most commonly eaten European species is Salsola soda known in Italy as Barba di Frate or Agretti. In Japan, S. komarovii is a crop of moderate importance, known locally as okahijiki (literally "land hijiki").

The seeds are also edible, although difficult to collect in quantity, and are sometimes ground into flour.

Tumbleweeds in culture

In film and television shows, a tumbleweed blowing across a scene can be used to indicate a deserted location or to emphasize an awkward silence, usually after an unsuccessful joke.

"Tumbling Tumbleweeds" was a hit for the cowboy singing group Sons of the Pioneers.

"Tumbleweeds" is a comic strip set in the Old West. It is also the title of a 1925 western movie.

"Tumbleweed Elementary School" in Palmdale, California is named after the plant species.

Tumbleweeds in science

NASA purchased a number of tumbleweeds to study their movement during the development of the Mars Tumbleweed rover.^[3][4]

List of species

More than 100 species have been proposed by botanists as belonging to Salsola.^[5] A partial listing of these species is given below. As of 2007, only six of these species (S. collini Pallas, S. kali L., S. paulsenii Litv., S. soda L., S. tragus L., and S. vermiculata L.) are listed as "reviewed" by the Global Biodiversity Information Facility.

References and external links

1. ^ Mosyakin, Sergei L. (2007). "Salsola," in Flora of North America: North of Mexico Volume 4: Magnoliophyta: Caryophyllidae, part 1, Editorial Committee of the Flora of North America (Oxford University Press, 2004). ISBN 978-0195173895. Online versions retrieved May 22, 2007.
2. ^ Pyankov, V. I., Artyusheva, E. G., Edwards, G. E., Black, C. C., & Soltis, P. S. (2001). "Phylogenetic analysis of tribe Salsoleae of Chenopodiaceae based on ribosomal ITS sequences: Implications for the evolution of photosynthesis types." Amer. J. Bot. 88: 1189-1198 (2001). Available online here; retrieved May 21, 2007.
3. ^ "People of the Web - Rolling in cash" (2007-11-20). Retrieved on 2007-11-27.
4. ^ "New way to explore the surface of Mars" (2003-05-13). Retrieved on 2007-11-20.
5. ^ Global Biodiversity Information Facility (2007). "Salsola" webpage retrieved May 21, 2007.

Further reading

• Everitt, J.H.; Lonard, R.L., Little, C.R. (2007). Weeds in South Texas and Northern Mexico. Lubbock: Texas Tech University Press.  ISBN 0-89672-614-2