Russian thistle is a large and bushy annual broadleaf plant that is common in the Mojave Desert.
It is also known as tumbleweed or windwitch. Dried ones tumble across desert landscapes, driven by the wind, a recurrent display of desolation in the American Southwest.
The plant is edible and serves as a food source to some livestock which graze in the desert but it is also, paradoxically, poisonous if eaten in too great of a quantity.
Known by the scientific name Salsola tragus, it occurs throughout the western states, most often in dry areas. Recent taxonomic work has demonstrated that what has been named Salsola tragus likely consists of several morphologically similar species that differ in flower size and shape. Besides S. tragus, these include S. australis, S. iberica, S. kali, S. pestifer, and S. ruthenica.
Russian thistle arrived in the United States in the early 1870s by means of Russian immigrants who inadvertently were carrying some Salsola seed in with their flax seed. It took root in southern South Dakota in Bon Homme County, where the newly arrived immigrants raised flax. By 1873 local botanists identified the new weed. By 1895 it had reached from the remote north middle of the country to New Jersey and California.
Russian thistle today is common throughout California, especially in the southern region, to an elevation of 8,900 feet. It grows best on loose sandy soils and inhabits agricultural land, roadsides, and other disturbed places.
When consumed in moderate amounts, immature plants are nutritious for livestock. However, with maturity and under particular conditions, some Salsola species accumulate levels of oxalates toxic to livestock, especially sheep. Most often toxicity occurs when sheep feed almost exclusively on these species for many weeks. Russian thistle also can create a fire hazard or hinder traffic when it breaks off from its main stem and dries up. At this stage, it is commonly called tumbleweed. It is also an alternate host for the beet leafhopper, Ciculifer tenellus, which vectors the virus that causes curly top disease in melons, tomatoes, sugar beets, and other crops. Common soil-applied, preemergence herbicides generally provide good control of this weed, but the seeds can germinate from up to 2.5 inches deep, so control may be poor where incorporation is shallow.
Stems are slender and flexible and often have reddish purple streaks. The seed leaves, known as cotyledons, and first true leaves are long and thin, like pine needles. The cotyledons are 2/5 to 1-2/5 inches long. Later leaves are soft and fleshy with a weak spine at the tip. Leaves are alternate to one another along the stem, but may appear opposite to one another because of the short length between stem joints. Later leaves are soft and fleshy, with small spines at the tips. Stems are thin, flexible, and often have reddish purple striations.
Young plants are usually taller than wide. Their lateral branches are shorter than the main stem and point upward.
As the plants mature, they are large and bushy with rigid, purple-streaked or green stems that typically curve upward, giving the plant an overall round shape. They generally grow to about 3 feet tall but can grow much larger, usually with a similar height and width, or taller than wide. Leaves are somewhat bluish green, fleshy to leathery, hairless or covered with stiff short hairs, and 1/3 to 2 inches long and up to 1/25 of an inch wide. Leaf tips are sharply pointed to spine tipped. Upper stem leaves or bracts are reduced, stiff, and prickly. After they turn grayish brown, the plants break away from the roots at the soil line, becoming tumbleweeds that scatter their seeds as the plant skeletons are blown around.
The flowers bloom from July through October. Flowers are produced in the junction or axils between the leaf base and the stem. Although they lack petals, they have an outer whorl of winglike sepals that are translucent, petal-like, fan shaped and often pinkish to deep red with noticeable veins.
Salsola kali is a host plant of the Sugar Beet Leafhopper. This insect carries curly-top virus, a disease affecting sugar beets, tomatoes, and beans.
Tumbleweeds produce an inedible fruit. The Russian thistle’s fruiting structures contain one seed, are somewhat round, and can grow to 3/10 of an inch in diameter—including the winglike sepals. Sepal wings are open and flat or folded over.
Seeds are compressed and round to somewhat conical, gray to brown, and have a thin, translucent seed coat, through which a dark, greenish-brown coiled embryo is visible.
The plant reproduces by seeds, which are spread as the tumbleweed tumbles.
The wiry, tough, sharp, pin prickly and irritating Russian Thistle is edible. Its young shoots and tips can be eaten raw and are actually quite palatable. They are better when cooked like greens. As the plant ages it becomes too tough to consume and the fat and pointed leaves will irritate your throat.
Because it can contain as much as 5 percent oxalic acid, those sensitive to oxalic acid should avoid it. It is also a severe allergen for some people.
To make steamed Russian thistle, take two cups of shoots or tips, rinse and steam them as they are or cut them up and steam. They can be seasoned with butter.
One can make Russian thistle broth by assembling five cups chicken broth, two cups Russian thistle tips or shoots, one potato or Jerusalem artichoke, one onion, a half cup parsley, a half cup chopped watercress, three chopped cloves of garlic, and one bay leaf.
Simmer the potato or Jerusalem artichoke in the broth. Add the chopped onion and garlic. Cut the Russian thistle into one inch pieces, chop the parsley and watercress, and add the whole bay leaf. Simmer for 20 minutes or until the potato is done.
A tumbled rice and Russian thistle dish uses four cups of Russian thistle, one cup rice, one cup mustard or radish leaves or any mild green, one teaspoon pepper, one teaspoon garlic powder and a third of a cup of jack or similar cheese shredded.
Cook the rice and steam the Russian thistle tips or shoots. After a few minutes add the rest of the greens to the thistle tips. When the greens are cooked, mix with the rice, season, sprinkle with the cheese. Serve hot.