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
Current Distribution: All states with the exception of
FL, AK and PR; also
Site and Date of Introduction: Introduced
into the
Mode(s) of
Introduction: Salsola tragus seeds were shipped from
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
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:
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