General:
Perennial herb from stolons or subrhizomes; often forming mats or clumps 10-40 cm wide; stems prostrate, branched, usually densely glandular-hairy above and in the inflorescence, glabrous to hairy below the nodes, the flowering stems decumbent to erect, 5-40 cm tall/long.

Leaves:
Basal leaves lacking; stem leaves opposite, mostly linear to lance-linear, 1-3 cm long, 1-7 mm wide, 1-nerved, greyish-green; with sterile branches arising in most leaf axils; stipules lacking.

Flowers:
Inflorescence of 3-6 flowers in an open cluster, rarely single; bracts of the inlorescence papery-margined; petals 5, white, egg-shaped, 8-12 mm long, deeply 2-cleft; sepals 5, oblong-lanceolate, 4-6 (7) mm long, glandular-hairy.

Fruits:
Capsules cylindric, 6-10 mm long, 10-valved; seeds golden to reddish-brown, 0.8-1.2 mm long, pimply.

Notes:
Highly variable, often confused with C. beeringianum.

Source:  The Illustrated Flora of British Columbia