Tumbleweed (Russian Thistle)
 Family Chenopodiaceae
Salaosa iberica
Designation/Status
Arizona Priority Weed List -
Not Listed
Federal Noxious Weed List – Not Listed
Origins
Eurasia
Plant Characteristics
Life Cycle: Seed producing. Seeds are
spread as mature plants break off at ground level and are
scattered by wind as tumbleweeds. Rapid germination and seedling
establishment occur following
precipitation.
Visual
Appearance: Rounded, bushy, multi branched annual 0.5 to 3
feet tall. Stems are usually red or purple striped. Leaves are
alternate, the first are long, string-like and soft, with later
leaves short, scale-like and tipped with a stiff spine.
Inconspicuous green flowers are borne in axils of upper leaves,
each flower accompanied by a pair of spiny bracts.
Habitat
Well
adapted to cultivated dry land agriculture, fields, overgrazed
pastures, roadsides, waste places, and disturbed sites on nearly
all soil types.
Control Measures
Mechanical and Cultural: Hand pull or till under
lightly in the early spring.
Biological: Control
agents to reduce this weed population consist of two predators,
Coleophora klimeschiella, a foliage feeding case bearing moth,
and C. parthenica, a stem boring moth. Both of these
species minimize the spread of Russian thistle by reducing seed
potential.
Chemical: has been shown
to develop a resistance to ASL inhibitors (sulfonylurea).
Effective pre-emergent chemicals include: Bromacil, Diuron, and
Hexazinone. Effective post-emergent chemicals include: 2,4-D
amine and ester formulations and Glyphosate.
Other Points of Interest
May be poisonous to
livestock because it contains nitrate, which bio-accumulates in
animals, causing several types of illness. Introduced to America
in the late 1800s. It is now one of the most common and
troublesome weeds in the drier regions of North America.
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