April 2013 18
Taxonomic Information System at itis.gov. The USDA database has location information for plants in the U.S. and Canada and uses the species names accepted by the ITIS. In the world of scientific naming of plants, all is not straightforward. Of the 22 species names put forward by scientists for species of the Russian thistle, only 11 have been accepted by ITIS as truly separate species or subspecies. Even so, Salsola species are found on every continent except Antarctica, and can be found everywhere from sea level to up to 8,500 feet. There are 7 species in the USDA database, of which three are found in Texas, two of these also living in the Four Corners states. The two species shared by all of the southwestern states are Salsola tragus, the prickly Russian thistle, and Salsola collina, slender Russian thistle. Texas also has Salsola kali, Russian thistle. Knowing that even scientists differ in the names they give to the plants they describe, I can’t be sure that the information I have gathered is accurate for the southwestern species, but there are similarities to all of them that apply to our tumblin’ tumbleweeds.
Mature Tumbleweed
-National Geographic
Tumbleweed Seedling
-Texas A&M Agrilife Extension