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.

Flowering spring--late summer. Moist areas near coast; 0--700 m; B.C.; Calif., Oreg., Wash.