|Hrusa, G. Fredric -|
|Cristofaro, Massimo -|
Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: December 31, 2009
Publication Date: February 7, 2010
Citation: Smith, L., Hrusa, G., Gaskin, J.F., Bruckart, W.L., Berner, D.K., Cristofaro, M. 2010. Six Species of Salsola tumbleweeds (Russian thistle) in the Western USA and Prospects for their Control. Weed Science Society of America Meeting Abstracts. Technical Abstract: Russian thistle or tumbleweed is a common alien weed in many parts of the western USA. However, the taxonomy of this weed has been very confusing. Recent morphological and molecular genetic studies of plants found in California have revealed the existence of at least five distinct species. Salsola tragus, is the most common and widespread tumbleweed. Salsola australis occurs primarily in California, and may be native to Australia(!). Salsola collina occurs east of the Sierra and Rocky Mountains. Salsola paulsenii occurs in desert conditions. Salsola ryanii appears to be an allopolyploid derivation involving tetraploid S. tragus and diploid S. australis. Salsola x gobicola appears to be a derivative of hybridization between S. tragus and S. paulsenii. Salsola kali is restricted to east and south coast seashores, and does not occur on rangeland or rights-of-way. The six recognized species of tumbleweeds differ in morphology, genetics and ecology; however, almost nothing is known about differences in their responses to management methods because of prior taxonomic confusion. The eriophyid mite Aceria salsolae and the fungal pathogens Colletotrichum gloeosporoides and Uromyces salsolae are being developed as classical biological control agents.