Russian thistle
(Salsola tragus)
Overview
- 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.
Selected Images
Maps
EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org
State List - This map identifies those states that list this species on their invasive species list or law. For more information, visit Invasive.org
Invasive Listing Sources
- California Invasive Plant Council
- California Noxious Weeds
- Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
- Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
- Ohio Noxious Weeds
- WeedUS - Database of Plants Invading Natural Areas in the United States
Taxonomic Rank
| Kingdom: Plantae |
| Phylum: Magnoliophyta |
| Class: Magnoliopsida |
| Subclass: Caryophyllidae |
| Order: Caryophyllales |
| Family: Chenopodiaceae |
| Genus: Salsola |
| Subject: Salsola tragus L. |
Synonyms and Other Names
Other Common Names:
prickly Russian thistle
Related Scientific Names:
Salsola iberica L. (Synonym)
Salsola kali ssp. tenuifolia Moq. (Synonym)