Annual herb, rarely persistent for more than a year, from a short, slight taproot; not matted; stems decumbent to erect, solitary to several, much branched, more or less glandular-hairy, 10-30 cm tall.
Basal leaves few, soon deciduous; stem leaves opposite, linear awl-like, 3-20 mm long, 3-nerved, glabrous, the primary ones mostly with clustered secondary leaves or short branches in their axils; stipules lacking.
Inflorescence of several to numerous flowers in an open, often diffuse cluster frequently more than 1/2 the total height of the plant, with awl-like bracts; petals broadly egg-shaped, from only slightly to 1.5 times longer than the sepals; sepals lanceolate, long-pointed or abruptly sharp-pointed, 3-nerved, 2.5-3.5 mm long.
Capsules egg-shaped, 3.5-4.5 mm long, 3-valved; seeds about 0.6 mm long, brown, finely pimply in a paving-block pattern.
Source: The Illustrated Flora of British Columbia