Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to western Montana.
Habitat: Shallow water and muddy shores, and in other wet places in the valleys and plains.
Conservation Status: Not of concern
Fibrous-rooted annual, the stem simple or branched, erect or diffuse, 0.5-2 dm. tall, glabrous.
Leaves opposite, sessile, pointed, entire or with a few small, sharp teeth, 1-4 cm. long and 2-15 mm. wide, on pedicels 1-3 cm. long.
Flowers solitary, on long pedicels arising in the axils of reduced upper leaves; calyx of 5 distinct sepals, narrow, pointed, 7-12 mm. long; bracteoles wanting; corolla tubular, bilabiate, 5-7 mm. long, the tube white or yellowish, the limb purplish, the upper lip slightly notched, the lower 3-lobed; fertile stamens 2, the others wanting, the pollen sacs parallel on a flattened surface inside the corolla tube.
Capsule dehiscing by 4 valves, nearly globose, not pointed, 4-5 mm. long.