Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Idaho and Nevada..
Habitat: Vernally moist meadows and other moist sites, from the lowlands to moderate elevations in the mountains.
Flowers: May-August
Origin: Native
Growth Duration: Annual
Conservation Status: Not of concern
Pollination: Bumblebees, bees, hummingbirds
Annual, the stem 1-4 dm. tall, usually simple; herbage spreading-hairy throughout, with hairs up to 2 mm. long in the inflorescence.
Leaves alternate, all cauline, 1-4 cm. long, the lower linear and entire, the upper a little wider and 3-5 cleft, the segments narrow.
Inflorescence a terminal spike; bracts gradually differentiated from the leaves, becoming shorter and more cleft, usually green throughout; calyx 2-cleft, with bifid segments; corolla off-white or pale yellow, 12-20 mm. long, exerted, the lower lip inflated and tri-saccate, with inconspicuous teeth; the upper lip straight, 1-2 mm. longer than the lower lip; stamens 4, attached near the top of the corolla tube.
Capsule.
PNW Herbaria: Specimen records of Castilleja tenuis in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Castilleja tenuis checklist entry
OregonFlora: Castilleja tenuis information
E-Flora BC: Castilleja tenuis atlas page
CalPhotos: Castilleja tenuis photos