Alternative common names:
Russian thistle, rolypoly, saltwort, windwitch, tumbleweed, common saltwort, and prickly glasswort, kakiebos, taaibos, tolbos.
Tumbleweed is an annual weed that begins life as a typical multiple branched bushes, which then takes on a spherical form. It depletes soil moisture and interferes with cultivation operations. This species invades roadsides, disturbed sites, riverbanks, riverbeds, in dry or somewhat saline areas. Flowering occurs from September-April.
Where does this species come from?Europe, North Africa, the Middle East, Central Asia, China and Australia.
What is its invasive status in South Africa?NEMBA category 1b
Where in South Africa is it a problem?Western Cape, Northern Cape
How does it spread?Mature plants break off at the ground, forming "tumbleweeds" rolling along the ground during windy conditions, scattering seeds.
Why is it a problem?
It's a highly problematic, tough, unpalatable plant that clogs up storm water channels and competes with native species. It can rapidly colonise new areas, especially overgrazed, bare and eroded soil. The plants are unpalatable leading to selective grazing by domestic stock which exacerbates existing overgrazing and opens the way for further tumbleweed invasion.
What does it look like?
Leaves:- Leaves are alternate; blades linear, 1-2 mm wide, fleshy, usually not swollen at base, apex acuminate, forming a rather firm spine, 1-1.5(-2.2) mm long.
Flowers: - Inconspicuous, white, yellowish or greenish, cup shaped, in the leaf axils.
Fruit/seeds: - Capsule - Small, brownish capsules, usually with five spreading membranous, veined wings. A single plant can produce up to 200,000 seeds.