General:
Perennial herb from a rhizome and tuberous-thickened root; stems erect, simple or few, branched above, hairless below the inflorescence or with a few coarse, spreading hairs, 0.6-2 m tall.

Leaves:
Basal leaves lacking; lower leaves opposite; upper leaves alternate, lanceolate to linear, short-stalked, rough-hairy, 8-16 cm long, 6-30 mm wide, entire, flat, 3-nerved at the base.

Flowers:
Heads with ray and disk flowers, solitary to few, terminal; involucres 1.0-2.0 cm tall; involucral bracts lance-linear, loose, inconspicuously hairy on the margins; ray flowers 10-16, 1.5-3 cm long; disk flowers yellow; receptacles convex to low-conic.

Fruits:
Achenes moderately compressed, usually glabrous; pappus of 2 readily deciduous awns with enlarged, thin, papery bases.

Source:  The Illustrated Flora of British Columbia