Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California.
Habitat: Shady, vernally (springtime) moist places on cliffs and ledges, especially at low elevations; often growing in moss mats.
Conservation Status: Not of concern
Annual, glandular-hairy to somewhat glabrous (smooth), growing to 0.5-3 dm. in height. The plants are slender, and have either a simple or freely-branching form. Often found growing in uniformly dense patches. The stems frequently appear somewhat reddish.
Opposite, slightly to evidently-toothed, 3-5 prominent veins on the upper surface. The blades are 0.5-2.5 cm. long, with a petiole of more or less equal length.
The yellow corollas fuse to form an upper and lower lip (bilabiate), and grow 8-14 mm. long. A conspicuous reddish-brown blotch is found on the lower and sometimes the upper lip. Individual flowers are attached to the stem by a long pedicel.
The reddish-brown blotch on the lower lip is very diagnostic along with its annual life cycle and tendency to be found in moss mats. The middle lobe of the lower lip tends to be the longest and somewhat curved backwards (deflexed). The lower two teeth of the calyx tend to be more rounded and longer than the upper three calyx teeth.