Family: Amaranthaceae (formerly Chenopodiaceae)
Tumbleweed is a bushy summer annual herb. It has a spreading taproot. This plant has numerous slender stems that vary from 8 to 36 inches in length and usually have reddish to purplish stripes. The stems are very bushy and branchy. Tumbleweed has regular small flowers that are white or membranous perianth consisting of 5 segmetns. Its brown, cup-shaped fruit that is 4 mm long. Seedlings have finely dissected leaves that almost look like pine needles. Fleshy green leaves start to get shorter right before getting woody. During July through October tumbleweed will dry out. It can grow to be 18 inches to 6 feet in diameter. The stem breaks off at soil level in the fall and early winter. Dried out circular bushes tumble along dispersing seeds.
Tumbleweed or Russian Thistle has a seed that will uncoil when the proper temperature is reached (52 to 90 degrees Fahrenheit). It will germinate successfully in loose soil which include: vacant lots, abandoned gardens, and agricultural fields, roadsides, fence lines-any open site with loosened soil. During the first year 90% of the seeds will either germinate or decay. With minimal moisture the seeds can develop taproots within 12 hours. This plant is extremely drought tolerant and the taproot can extend several feet into the soil. As the plant matures the leaves go from fleshy pine like needles to short and spiny, making it much easier for the plant to conserve moisture. Tumbleweed produces more than 200,000 seeds. When the conditions are poor it will become very competitive.
Tumbleweed is a pest species because it can reduce yield and quality of numerous crops like alfalfa and small grains. This plant depletes the moisture in the soil, interferes with tilling, and is a source of food and shelter for insects, vertebrate pests, and crop diseases (curly top). It will threaten native plant ecosystems. This plant will take many hours of man power to remove and control. It is a good source of fuel for wildfires, rapidly spreading it as the weed tumbles along. Many people are sensitive to tumbleweed and develop skin rashes. A slight scratch from the plant can cause itching and reddened patches of skin. The pollen being blown in the wind can cause allergic reactions in some people.