General:
Annual herb from a taproot; stems erect, solitary, simple or slightly branched, round, smooth, 5-20 cm tall.

Leaves:
Basal leaves few, soon deciduous; stem leaves in whorls of 4, with one pair smaller, upper leaves sometimes opposite, lanceolate to linear-elliptic, larger leaf pairs 1-2 cm long, smooth, 1-veined, entire, unstalked.

Flowers:
Inflorescence of solitary, stalked, axillary flowers; corollas white, cup-shaped, 3.5-7 mm wide, 3-lobed, soon deciduous; calyces obsolete.

Fruits:
Nutlets, 2, 2.5-3.5 mm long, with numerous, short, hooked hairs.

Source:  The Illustrated Flora of British Columbia

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  The Illustrated Flora of British Columbia