Russian thistle

Salsola tragus L.

Description from Invasive.org

Appearance
Salsola tragus is an annual herb that can grow to 4 ft. (1.2 m) tall. It was introduced into the United States in the mid 1870s, possibly as a contaminant in flax seed.
Foliage
Leaves are alternate and narrow. Upper leaves have a sharp point at the apex and are 1.3-2 in. (3.3-5.1 cm) long.
Flowers
Flowering occurs from midsummer to fall, when small, pink to greenish flowers develop from the leaf axils. Each flower is subtended by 3, spine-tipped leaves.
Fruit
Fruits are 0.19-0.31 in. (4.8-7.9 mm) in diameter including the wings. Wings are opaque with smooth margins and veins.
Ecological Threat
After Salsola tragus matures it detaches from the root system and tumbles in the wind, spreading seed (like another common name “tumbleweed” suggests). It is native to Eurasia.

Resources


Selected Images from Invasive.org

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Plant(s) habit with Puu o Kali in background
Forest and Kim Starr, Starr Environmental, Bugwood.org
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Flower(s) capsules
Forest and Kim Starr, Starr Environmental, Bugwood.org
Additional Resolutions & Image Usage
Flower(s)
Forest and Kim Starr, Starr Environmental, Bugwood.org
Additional Resolutions & Image Usage
Plant(s)
Mary Ellen (Mel) Harte, , Bugwood.org
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Feature(s) Stem and foliage
Mary Ellen (Mel) Harte, , Bugwood.org
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Feature(s) Spines
Mary Ellen (Mel) Harte, , Bugwood.org
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Seedling(s)
Utah State University , , Bugwood.org
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Seed(s) capsules
Forest and Kim Starr, Starr Environmental, Bugwood.org
Additional Resolutions & Image Usage
Seedling(s)
Forest and Kim Starr, Starr Environmental, Bugwood.org
Additional Resolutions & Image Usage
Plant(s) small plant
Forest and Kim Starr, Starr Environmental, Bugwood.org
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Infestation infestation
Forest and Kim Starr, Starr Environmental, Bugwood.org
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Plant(s) Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 2: 25.
USDA NRCS PLANTS Database , USDA NRCS PLANTS Database, Bugwood.org
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Distribution