Introduced Species Summary Project
 Tumbleweed (Salsola tragus)


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Common Name: Tumbleweed (Russian thistle or Russian tumbleweed, Windwitch)

Scientific Name: Salsola tragus

Classification:                                                                     mature plant

Family: Chenopodiaceae
Genus: Salsola


Identification: A noxious bushy summer annual that grows to approximately 1m in height and width and after flowering and drying out, the plant breaks at the soil line and becomes a “tumbleweed” and is blown about, thereby dispersing the upward of 250K seeds in the mature plant.   The mature plant has stiff, needle-like upper stem leaves that alternate.  Salsola comes from the Latin sallera, “to salt”.  The plant is salt tolerant. 

    seeds                   flower                    seedling

Original Distribution:   Arid steppes of the Ural Mountains of Russia; also Africa, Asia and Europe

Current Distribution: All states with the exception of FL, AK and PR; also Canada and Australia

Site and Date of Introduction: Introduced into the US in South Dakota in 1874

Mode(s) of Introduction: Salsola tragus seeds were shipped from Russia with flax seeds  

Reason(s) Why it has Become Established:  Wide dispersal of seeds via tumbling mature plants containing hundreds of thousands of seeds; also via railroad transportation of cattle.  Seeds germinate readily in sandy, dry, salty soil conditions in temperatures between 28 – 110 degrees F along roads, and in abandoned or cultivated fields.  By autumn the plant is maximum size and has flowered and has begun to dry out.  Once dry, and brittle, the main stem breaks and it begins to tumble.  It exploited the early western farmers removal of the native prairie grasses with the resulting barren plains ideal for the tumbleweeds’ seed dispersal.

Ecological Role: Can be a host for beet leafhopper that carries virus that causes curly-top of sugarbeets, tomatoes and melons.

Benefit(s): Immature plants can provide forage for livestock.  Historically burned to make soap.  Used in making glass and as a medicinal.  The Sons of Pioneers made the song “Tumbling Tumbleweeds”, drawn from a poem of the same name published in the University of Arizona literary quarterly, popular in the 1940s.

Threat(s):  As seedlings Salsola tragus infests spring wheat fields and can crowd out up to half of the cash crop.   As a tumbleweed it can be a road hazard when blown across roads or into a moving vehicle.   The plant skeleton can persist up to a year and gathers in unsightly numbers along fences, buildings and other structures.

Control Level Diagnosis: The species needs continued control.  Due to its wide-ranging seed dispersal and ability to grow in inhospitable conditions, Salsola tragus and its numerous related species, requires Highest Priority control.

Control Method: One method of control is to cut the seedling above the cotyledon.  This prevents seed production and controls infestations.  The cultivation process, however, needs to be repeated until the seed bank is depleted.  Tillage is also used, but it can facilitate seed germination as the seeds can germinate up to three years following dispersion.  Two insects, the leaf mining moth and a stem boring moth have been approved and released in CA for control of Russian thistle.  The stem boring moth has not proved effective, and there is no data to date on the effectiveness of the leaf mining moth.  Roadside seedlings have been effectively controlled by herbicides.
 

References & Photo Credits:   

·         www.plants.usda.gov/cgi_bin/plant_profile

·         www.cdfa.ca.gov/phpps/ipc/weedinfo/salsola.htm

·         www.desertusa.com/mag01/may/ppr/tweed.html

·         www.issg.org/database/species/ecology.asp

·         www.invasivespecies.net/database/species/ecology.asp

 

Author: Hersey Egginton
Last Edited: November 14, 2005


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