Tumbleweeds are a predator
weed that invades disturbed soil all across the country.
It is also called Russian Thistle or Wind Witches. The plant gets it Latin
from the word sallere, meaning salt, because it tolerates salty soil.
Russian Thistle arrived in
the United States about 150
years ago when farmers
South Dakota imported contaminated flaxseed from Russia. Ever since it
has steadily taken root across the country, exploiting native ecosystems.
Virtually everyone recognizes
a mature Russian thistle, which looks like the skeleton of a
normal shrub. Plants may be as small as a soccer ball or as large as a
Most people, however, would fail to recognize the seedling and juvenile
plant’s bright green,
succulent, grass-like shoots, which are usually red or purple striped.
Inconspicuous green flowers grow at axils (where leaf branches off of
stem) of the upper leaves,
each one accompanied by a pair of spiny bracts.
Mice, bighorn sheep and pronghorn eat the tender shoots.
When it dries, it rolls around
and disperses seeds. Each plant averages about 250,000 seeds,
which is why transporting or composting the plant at this stage is a problem.
It is best to get rid of the plants while it is still green.
There is an excellent article
in the National Geographic
"The Weed That Won The West". December 2013 issue.