General:
Perennial herb from a rhizome and branched, somewhat woody stem-base; stems erect to ascending, 20-80 cm tall, sometimes branched above, sparsely soft-hairy.

Leaves:
Basal leaves several, 5-20 cm long, pinnately compound, with stipules fused to base of long leaf-stalks and forming membranous margins; leaflets 9 to 17, oval to round-oblong, 0.5-2 cm long, coarsely saw-toothed; stem leaves alternate, few, reduced upward, the upper with free leaflet-like stipules.

Flowers:
Inflorescence a dense, egg- to globe-shaped, long-stalked spike, 7-25 mm long, of several to many small flowers, the lower flowers male, the upper female or bisexual; corollas absent; calyces green, often purple-tinged, 4-lobed, the lobes elliptic, 3-6 mm long; ovaries superior; stamens about 12, the filaments thread-like, long-exserted, drooping.

Fruits:
Achenes, enclosed in the 4-angled, distinctly winged, net-veined and rough-warty hypanthium.

Source:  The Illustrated Flora of British Columbia