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Tartar thistle

Kali tragus
Starr 070313-5636 Salsola tragus.jpg
K.. tragus in tumbleweed mode
Scientific classification
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Amaranthaceae
Genus: Kali
Species: K. tragus
Binomial name
Kali tragus
(L.) Scop.
Synonyms

Salsola kali L. subsp. tragus
Salsola tragus L.


Salsola kali L. subsp. tragus
Salsola tragus L.

Kali tragus is a species of flowering plant in the family Amaranthaceae. It is known by various common names such as prickly Russian thistle,windwitch, or common saltwort. It is widely known simply as tumbleweed because in many regions of the United States, it is the most common and most conspicuous species of tumbleweed. Informally, it also is known as "salsola", which was its generic name until fairly recently.

Kali tragus is native to Eurasia, but in the 1870s, it appeared in South Dakota when flaxseed from Russia turned out to be contaminated with Kali seeds. Although it is the best-known of this group of weeds, and was at first thought to be a single well-defined species, it now is known to have included more than one species plus some hybrids. This has led to taxonomic confusion in dealing with species in the genera Salsola and Kali in America. Recent studies show that the population that once was assigned to Salsola tragus really includes three or more morphologically similar species that differ in flower size and shape. The group was widely assigned to the family Chenopodiaceae, but the Chenopodiaceae – including the genera Kali and Salsola – have since been included in the Amaranthaceae. They now are allocated to the Salsoloideae, a subfamily of the Amaranthaceae.

Kali tragus proved to be highly invasive as an introduced species and rapidly became a common ruderal weed of disturbed habitats in many regions of North America, particularly in the Midwest. The species also has become naturalized in various regions of Central and South America and in parts of Southern Africa and Australia. It now occupies a wide variety of habitat types in those regions and often is the first or even the only colonizer in conditions where no local species can compete successfully. Because of its preference for sand and its tolerance of salinity, it commonly grows along sea beaches as well as in disturbed grassland and desert communities, especially in semiarid regions.


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Wikipedia

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