Tumbleweeds

11/13/11


dry, dead tumbleweed
      Tumbleweed or Russian thistle is an annual plant known throughout the American west.  Tumbleweeds are plants of the Salsola genus, part of the Chenopodiaceae family, that are now included in the family Amaranthaceae.  Although native to Russia, the plants grow in many parts of the world.

     Tumbleweeds were first reported in the United States in the 1870's in South Dakota, apparently imported in shipments of flax seed.  Tumbleweeds like the dry, sandy soil of deserts.  They need only a little bit of moisture and warmth to grow.



green, growing Russian thistle
      Inconspicuous flowers bloom from July through October in the junction between the leaf base and the stem and are pinkish-red and white.



Russian thistle flowers

     Leaf tips are sharply pointed to spine-tipped.  Mature plants generally grow to about three feet and are large and bushy.  The stems curve upward giving the plant an overall round shape.


Russian thistle leaf tips

     When mature in autumn, the mostly dried up Russian thistle plant breaks away from its roots, and is now called a tumbleweed.  Because it is rounded, it is rolled or tumbled by the wind.  There is a purpose to this tumbling.  A tumbleweed can produce up to 250,000 seeds, and the tumbling serves to spread those seeds.

     There are hundreds of tumbleweeds strewn across the desert floor out here where I live.  Because of their rolling motion, tumbleweeds can damage the protective soil crust, and this can lead to subsequent wind damage and topsoil loss.  Tumbleweeds can also be a fire hazard if many of the dead plants collect along fence lines, or if ignited plants blow across fire lines.

tumbleweeds along a fence line

     In moderate amounts, the immature plants are nutritious for livestock.  Phytoremediation, or the use of plants to clean up pollution, could be a possible use for tumbleweeds.  They are one of the best accumulators of uranium from the soil, and could be used to clean up soil contaminated with it.

      Tumbleweeds can also be a source of entertainment.  The song Tumbling Tumbleweeds was made popular by the Sons of Pioneers in the 1940's.

5 comments:

  1. What a fine explanation of the workings of a plant that is so evocative of the Western desert. And, an engaging illustration of nature's supreme talent for reproducing itself.

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  2. Thanks, Lee. Tumbleweeds are unique plants. There are so many out here, I had to research them to satisfy my own curiosity.

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  3. Very interesting post. Living on the coast, I don't get to see any desert flora. Tumbleweeds seem rather exotic to me.

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  4. L. Ambler, I love the interesting and informative details you include in your thoughtful posts.

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  5. Anita,

    Thanks for visiting. Tumbleweeds are unique and interesting to me also.

    Anne,

    It was fun researching tumbleweeds. They are different.

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