Salsola tragus L.

by Brian McGinness, Native Plants Class 2003
Common names:
Russian thistle, tumbleweed
Family: Chenopodiaceae
Synonymy: Salsola iberica (Sennen & Pau) Botsch. ex Czerepanov, Salsola kali L. ssp. ruthenica (Iljin) Soó, Salsola kali L. ssp. tragus (L.) Celak, Salsola kali L. ssp. tenuifolia Moq
Salsola pestifer A. Nels. Salsola ruthenica Iljin
Etymology: Salsola means salty in Latin. Tragus could come from the Greek tragos referring to a part of the ear or a goat, or it could come from Hieronymous Tragus the Greek form of the name Jerome Bock, one of the fathers of German botany.

Identification
Growth form:
A bushy annual from 6” to 6’. Usually a little taller than wide with branches curving to produce an overall slightly spherical shape to the plant.
Roots: Russian thistle produces a fairly deep taproot, 1.5m, with a lateral width of 1.8m.
Stem: Stems are ridged and often have reddish hue to them.
Leaves: The young plants have long, ½ to 2”, thin, alternate leaves that drop off as the plant matures and are replaced by short awl-shaped leaves that are accompanied by sharp, pointed bracts.
Inflorescence/flowers: Male or bisexual flowers can be white, pink, red, purple, or even orange, in clusters at the base of leaves in upper branches. Flowers have no petals. 4-5 sepals with wing-like appendages and are persistent in fruit. Stamens extend beyond the sepals, exserted. They are wind pollinated and outcross or are self-fertile.
Fruit: Fruits are roughly spherical and are encased in the persistent sepals. Each contain a solitary seed that is spherical, slightly flattened or cone-shaped. The coiled embryo is visible through the translucent seed coat. An average plant can produce 2,000 seeds, a large plant can produce up to 100,000 seeds.
Similar species: See list of synonyms.

Ecology
Life history:
Annual.
Native/introduced: A non-native invasive plant considered noxious in most states. Original range includes eastern Russia and Mongolia. Thought to have arrived in the U.S. in shipments of flax seed about 100 years ago. Now a ubiquitous symbol of the American west.
Photosynthetic pathway:
Phenology:
Plants flower from early through late summer. When the seeds are mature the plant breaks from the roots at the crown and the whole plant is blown by the wind, tumbling and dispersing its seeds as it does.
Distribution: Found in every U.S. state except Florida. Usually associated with disturbed sites.

Uses
Young plants are edible for livestock and humans.

References
1. http://www.uapress.arizona.edu/online.bks/weeds/russiant.htm An Illustrated Guide to Arizona Weeds, The University of Arizona Press

2. Charters, Michael L. California Plant Names, Word Meanings and Name Derivations. www.calflora.net/botanicalnames/http

3. NRCS Plants Database. http://plants.usda.gov.

4. CDFA, California Weed Eradication Program. http://pi.cdfa.ca.gov/weedinfo/SALSOLA2.html