Rolling tumbleweed gif7/5/2023 ![]() ![]() This means that it can get caught up on fence lines and other structures, or in established vegetation where it can't compete. This means they can grow in places with naturally reduced vegetation, as well as manually cleared land.īut a tumbleweed doesn't choose where to go - it travels wherever the wind pushes it. These plants will grow in environments with extremely little moisture and are also adapted to alkaline and saline soils. The Russian thistle, however, only relies on temperature, needing a day temperature of about 20☌ and 5☌ at night to sprout. Many plants require a complicated set of stimuli for germination to occur, such as the correct light, humidity and temperature conditions. When the seeds fall in an ideal location, they have to wait for favourable conditions to be able to germinate. Separated from its root, the plant is dead, but its thousands of seeds survive for months and as the plant bounces along, the vigorous tumbles shake them from their protected home among the spiny branches, leaving trails of them in the plant's wake. With a gust of wind, it begins to roll, becoming a true tumbleweed. By the onset of frost its seeds have matured, and the plant cleanly breaks away from its root. The plant grows in a rounded shape, sometimes to over a metre tall. Today the plant is found in all states except Alaska and Florida. The arrival and spread of Russian thistle is considered to be one of the fastest plant invasions in the history of the United States. The seeds and plants could also travel considerable distances by floating along in irrigation canals and ditches.īy the turn of the twentieth century, Russian thistle had made its way to California, where overgrazing had depleted sagebrush desert of it native plants, leaving ample new habitat to exploit. With the help of the transcontinental railroad, they were able to spread hundreds of miles with no effort on their part. The seeds continued to contaminate consignments of grain. Russian thistle can spread prolifically and while it has its own very effective natural methods for doing so, its invasion of North America was at least in part facilitated by people.īy virtue of being about the same size, it was difficult to separate Russian thistle seeds from other cereal grains mechanically and threshing machines, which remove grain seeds from their stalks and husks, could inadvertently disperse the weed's seeds locally as they travelled between farms. The plant also affected native vegetation and wildlife, preventing them from thriving in infested areas. In some areas, infestations grew to the point that ploughing became impossible and there were extensive crop losses worth millions of dollars. Its defences put off grazing animals, but also inflicted wounds on farmers, their horses and livestock. As pioneer farmers cut down prairie grasses and other native vegetation to make space for crops, they created a suitable habitat for the invasive Russian thistle.Īs Russian thistle matures, it goes from a soft seedling to a stiff and spiny plant. This is exactly what it found in the ploughed land of the Great Plains. Russian thistle is an expert at exploiting loose, disturbed soil with little competing vegetation. It's thought to have arrived surreptitiously its inconspicuous seeds well hidden in a containment of flaxseed imported from what was then the Russian Empire.įarmers were among the first to notice its arrival. The Russian thistle made its first known appearance in North America in the 1870s, in Bonhomme County, South Dakota. It is instead native to dry and semi-dry regions throughout Europe and central Asia. Russian thistle isn't native to North America. How did tumbleweeds spread across North America? Its invasion was also, at least in part, one of our own making and we're still living with the repercussions of it. It has followed in the wake of agriculture and other human activities since the late 1800s and its ability to spread prolifically makes it a threat to ecosystems, human health, and the economy. Russian thistle is highly invasive in North America. This plant is an icon of the Old West, featured in movies, song lyrics and more, however, its representation in media may be somewhat misleading. Tumbleweed, wind witch and Russian cactus are among the many common names for the Russian thistle ( Salsola tragus) – though it isn't a thistle or a cactus at all and is instead part of the Amaranth family. ![]()
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