General:
Biennial, or more often perennial, scarcely aromatic herb from a taproot; stems erect, several to numerous, glabrous to hairy, 0.1-1.0 m tall.

Leaves:
Mainly basal, 2-3 times pinnately cut or 3-parted, 2-12 cm long, including the stalks, the segments linear or linear-filiform, seldom more than 2 mm wide, glabrous to more often long-hairy, reduced above.

Flowers:
Heads disciform, numerous in a branched or narrow inflorescence, involucres hemispheric 2-4.5 mm tall; involucral bracts glabrous to densely long-hairy; receptacles glabrous; female flowers 8-20, disk flowers 10-25.

Fruits:
Achenes glabrous.

Notes:
The taxonomy of this circumpolar species remains unclear, especially in North America. Many of the regional floras disagree with respect to the number of taxa that should be recognized (Douglas 1995). The two subspecies recognized for BC may be separated, although sometimes with difficulty, as follows:

1. Plants usually 10-40 cm tall; involucres 3-4.5 mm tall.......................ssp borealis (Pall) Hall & Clem.

1. Plants usally 50-100 cm tall; involucres 2-3 mm tall......................ssp. pacifica (Nutt.) Hall & Clem.

Source:  The Illustrated Flora of British Columbia