Distribution: Occurring east of the Cascades crest in south-central Washington; south-central Washington to north-central Oregon.
Habitat: Moist, grassy areas.
Conservation Status: Threatened in Washington (WANHP)
Tufted, perennial herbs, the stems simple, glabrous, 1.7-2.8 mm. wide and up to 3.2 dm. tall.
Leaves mostly basal, glabrous, narrowly linear, up to 2 dm. long.
Inflorescence borne singly, subtended by a pair of green, glabrous bracts, the outer 27-48 mm. long, 14-17 mm. longer than the inner, united at the base, the inner with the keel evenly curved, the tips obtuse to acute; tepals 6, pale blue, the bases yellow, 10-14 mm. long, oblong, rounded, with a short bristle; stamens 3, the filaments fused to near the tip; ovary inferior.
Capsule 3-celled, tan to medium brown, globose, 4-5 mm. long.
Sisyrinchium sarmentosum is known from only three or four populations in the Columbia River Gorge area of the Cascade Mountains. The pale blue flowers with rounded apices on the outer tepals set this species apart from others in the region.