General:
Perennial herb from a taproot and branching stem-base; forming loose mats to 20 cm across; stems decumbent to ascending, several, branched, glabrous, 5-15 cm tall.

Leaves:
Basal leaves linear to lance-linear, blunt, 0.4-1.5 cm long, less than 1 mm wide, 3-nerved, hairy-margined; stem leaves opposite, 1-6 pairs, 0.3-1.2 cm long, hairy-margined,often with secondary axillary leaves; stipules lacking.

Flowers:
Inflorescence of solitary flowers on glandular stalks; petals 5, oblong to egg-shaped, white or sometimes purplish, 0.8-1.3 cm long; sepals 5, green or often purplish, glandular-hairy to nearly glabrous, 2.5-4.0 mm long, obtuse.

Fruits:
Capsules 0.5-1.8 cm long, 3- to 4-valved; seeds 0.8-1.2 mm long, somewhat kidney-shaped, reddish-brown, roughened.

Source:  The Illustrated Flora of British Columbia