Herbs, perennial, cespitose, dark brown to black when dry, to 6.2 dm, not glaucous. Stems simple, 2–6.8 mm wide, glabrous, margins entire, similar in color and texture to stem body. Leaf blades glabrous, bases not persistent in fibrous tufts. Inflorescences borne singly; spathes mostly greenish, glabrous, keels entire; outer 13–53 mm, 2.2–9 mm longer than inner, tapering evenly towards apex, margins basally connate 3–8 mm; inner with keel straight to evenly curved, hyaline margins 0.5–1 mm, apex usually rounded, occasionally erose, ending 0.2–1 mm proximal to green apex. Flowers: tepals medium to bright yellow with brownish veins; outer tepals 12–18 mm, apex rounded or acute, aristate; filaments ± distinct, glabrous; ovary similar in color to foliage. Capsules dark brown to black, broadly fusiform or slightly turbinate, 6–13 mm; pedicel erect to ascending. Seeds hemispherical, with shallow depression on flattened side, 0.7–1.5 mm, rugulose. 2n = 32, 34, 36.
Phenology: Flowering spring–late summer.
Habitat: Moist areas near coast
Elevation: 0–700 m
B.C., Calif., Oreg., Wash.