Carduus acanthoides L.
plumeless thistle
Asteraceae (Aster family)
Introduction to Vascular Plants
plumeless thistle
Asteraceae (Aster family)
Introduction to Vascular Plants
SUBTAXA PRESENT IN BC
Carduus acanthoides ssp. acanthoides
Species Information
General:
Biennial herb; stems spiny-winged, branched above, 0.3-1.5 m tall.
Leaves:
Basal leaves lacking; stem leaves narrowly elliptic or oblong in outline, deeply lobed or pinnately cut, up to 25 cm long and 8 cm wide, sparsely hairy on main veins, spiny-margined.
Flowers:
Heads discoid, 1.5-2.5 cm wide, clustered or solitary and erect at the ends of branches; involucres hemispheric; involucral bracts linear-lanceolate, in 2-3 series, somewhat leafy and spreading, outer ones spine-tipped; disk flowers usually purplish, sometimes cream or white, nearly 2 cm long.
Fruits:
Achenes glabrous, egg-shaped, with 15-20 dark longitudinal lines and a lighter collar at the tip; pappus whitish with minutely finely-barbed bristles.
Habitat and Range
Moist to dry fields, roadsides or waste places in the montane zone; rare in E BC; introduced from Europe.Status Information
Taxonomic Keys
1. Heads large, 2-8 cm wide, nodding, solitary; involucral bracts 2-8 mm wide...................Carduus nutans ssp. leiophyllus
1. Heads smaller, 1-2.5 cm wide, ascending, often clustered, involucral bracts 1-1.5 mm wide....................Carduus acanthoides Source: Modified from The Illustrated Flora of British Columbia |