Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Baja California, east to Montana, Idaho, Utah, and Arizona.
Habitat: Gravelly prairies and stream banks to grassy hillsides at low elevations.
Growth Duration: Annual
Conservation Status: Not of concern
Usually glabrous, delicate, erect annual, the filiform stem up to 2 dm. tall, simple or branched below.
Leaves opposite, only on the lower half of the stem, linear or linear lanceolate, 5-10 mm. long; basal leaves with a small ovate blade 3-8 mm. long and a petiole at least as long.
Flowers in a large, open inflorescence with membranous bracts and filiform pedicels; sepals 5, 3-4 mm. long, lanceolate, pointed, 3-nerved, with transparent margins; petals wanting or very small.
Capsule narrowly cylindric-ovoid, shorter than the sepals.