Regional Noxious. Annual.
Russian thistle (tumbleweed) grows in rounded bushes with many
branches, and red or purple-striped stems. Flowers are inconspicuous,
but each bloom has a pair of spine-tipped bracts.
The leaves are also tipped with a sharp point. Mature plants are 0.1-1m
Russian thistle is well adapted to cultivated dry land agriculture,
but is also found on disturbed rangeland and other disturbed habitats.
This weed colonizes barren desert areas that cannot support other flora
and invades many different disturbed plant communities.
In British Columbia, Russian thistle grows at low to mid-elevations
along roadsides, railroad tracks, fields, and disturbed
or unoccupied sites. It cannot tolerate saturated soil for extended periods.
It is common in southern areas of the province.
After seeds mature in the autumn the plant stem separates from the root,
and the plant spreads its seed as it tumbles in the wind. A single plant
can produce over 200,000 seeds.