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Russian Thistle Tumbleweed

- March 12, 2018
"Tumbleweed," "Russian thistle" and "wind witch" are typical names for this symbol on the American west. Russian thistle alludes to its Eurasian origin. Scientific names for tumbleweed consist of Salsola kali, S. pestifer, S. australis, S. iberica, and S. tragus. Salsola is derived in the Latin sallere, "to salt," in reference for the plant’s salt tolerance. There will not however appear to be a consensus around the preferred scientific name, even though S. tragus may be the major candidate for the inland range of tumbleweed and S. kali, for the more coastal selection.

Description


Practically everybody recognizes a mature Russian thistle, which looks like the skeleton of a standard shrub. Plants may be as modest as a soccer ball or as big as a Volkswagen beetle. Most people, however, would fail to recognize the seedling and juvenile plant’s vibrant green, succulent, grass-like shoots, that are generally red or purple striped. Inconspicuous green flowers grow at axils (where leaf branches off of stem) in the upper leaves, each and every 1 accompanied by a pair of spiny bracts. Mice, bighorn sheep and pronghorn eat the tender shoots.

Russian Thistle Tumbleweed

Habits/Habitats


Since it rolls down a desert road, Russian thistle plants do what they do best, disperse seeds, which normally number 250,000 per plant. Seeds are uncommon in that they lack any protective coat or stored food reserves. Alternatively, each and every seed can be a coiled, embryonic plant wrapped in a thin membrane. To survive winter without a warm coat, the plant will not germinate till warm weather arrives.

When moisture falls, the plant is ready to uncoil and germinate. All that's necessary are temperatures among 28 and 110 degrees Fahrenheit. It then quickly sends up two needle-like leaves and begins to shoot skyward. By autumn the plant has reached maximum size, flowered and begun to dry out. A specialized layer of cells in the stem facilitates the easy break among plant and root, as well as the journey starts anew.

Like many invasive weeds, Russian thistle exploited the destruction of native ecosystems. When farmers removed prairie grasses, they created a perfect atmosphere, smooth and flat, for a plant that could roll across the landscape dispersing seeds. Herbicides now control the spread of Russian thistle by disrupting the maturation method of the plant.

Range


Although tumbleweed is native to the arid steppes of the Ural Mountains in Russia, it's now ubiquitous all through the western states, growing in disturbed soils such as agricultural fields, irrigation canals and roadside shoulders and ditches. Plants thrive in salty and alkaline soils but will normally be outcompeted by natives in undisturbed habitats. Elevation range is from under sea level in Death Valley to over 8500 feet.

Tumbleweeds have been first reported in the United States around 1877 in Bon Homme County, South Dakota, apparently transported in flax seed imported by Ukrainian farmers. Inside two decades the plant had tumbled into a dozen states, and by 1900, tumbleweed had reached the Pacific Coast.

The peregrinating (hugely traveled) plant also grows abundantly in Afghanistan, Argentina, Australia, Canada, Chile, China, Egypt, Greece, Hawaii, Hungary, Indonesia, Iran, Italy, Japan, Lebanon, Mexico, Morocco, New Zealand, Norway, Pakistan, Poland, South Africa and Turkey.
 

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