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, exuding milky juice when broken, 0.6-2.5 m tall.

Leaves:
Basal leaves lacking; stem leaves alternate, pinnately cut or toothed, 10-40 cm long, 4-20 cm wide, sometimes hairy along the main veins, the upper ones with ear-like flanges at the base, clasping.

Flowers:
Heads with strap-shaped flowers, numerous in a narrow, elongate inflorescence; involucres 9-14 mm tall; involucral bracts lanceolate, graduated, often purplish at the tip, glabrous; ray flowers bluish to white, sometimes yellow, 13-34.

Fruits:
Achenes thin-edged, prominently nerved, beakless or shortly stout-beaked less than 1/2 the length of the body, 4-5.5 mm long; pappus brownish.