General:
Annual herb from a slender taproot; stems erect, 10-70 cm tall, usually simple or branched from the base, glabrous or hairy.

Leaves:
Linear to lanceolate, 1.5-5 cm long, entire; usually unstalked.

Flowers:
Inflorescence an open spike, loosely-flowered, buds erect; hypanthium 2-10 mm long; corollas bowl-shaped, tending to close at night; petals lavender to purple and often with a darker spot above, fan-shaped to elliptic, 5-15 mm long; sepals staying fused in 2's or coming free, usually bent back; fertile stamens 8, all alike; stigmas elliptic-oblong, about 1.5 mm long, lavender to purple or dark wine-red; stigma not exceeding anthers.

Fruits:
Capsules, 1-3 cm long, round or 4-angled, ribbed, densely hairy, short-beaked.

Source:  The Illustrated Flora of British Columbia