IDENTIFICATION
Regional Noxious. Winter annual or biennial.
Plumeless thistle stems are covered in leaf-like, spiny wings that
extend up the stem to the flower heads. Stem leaves are stalkless and
hairy underneath. Flowers are small, purplish-pink, and appear in small
clusters or alone at the ends of branches. Mature plants grow to 1.2 m.
DAMAGE
As with most thistles, livestock will rarely eat plumeless thistle
and large or dense infestations reduce available forage. Plumeless
thistle is one of the most aggressive thistles, due to its heavy seed
production.
HABITAT
Plumeless thistle grows in pastures, fields, disturbed habitats,
logged-over areas, and along roadsides at mid-elevations. In British Columbia,
it occurs in isolated pockets in the Thompson agricutural region, and
it is a major concern in the Kootenay and Omineca agricultural regions
in the province.
SPREAD
Seeds are mainly dispersed by wind.
