E-Flora BC: Electronic Atlas of the Flora of British Columbia

General:
Annual or biennial herb from a taproot; stems erect, branched above, usually solitary, glabrous or sometimes coarsely stiff-hairy, exuding milky juice when broken, 0.3-2.5 m tall.

Leaves:
Basal leaves lacking; stem leaves alternate, entire or toothed to pinnate, 10-35 cm long, 1.5-12 cm wide, triangular-shaped or narrowed at the base.

Flowers:
Heads with strap-shaped flowers, numerous in a narrow, elongate inflorescence; involucres 10-15 mm tall; involucral bracts lanceolate, graduated in 4-5 series, often purplish at the tip, glabrous; ray flowers yellow, 13-22.

Fruits:
Achenes blackish, flat, median nerve on each face, 4.5-6.5 mm long including the slender beak which varies from 1/2 as long to as long as the body; pappus white.