Culms sharply angled, at least 1 angle serrulate distally, 10-35 cm. Inflorescences with pistillate heads 2.5-5 cm wide; proximal spikes ascending-spreading to spreading. Pistillate scales reddish to brown with green or gold center, sometimes with distal margins white or pale gold, 0.1-0.3(-0.5) mm wide, apex short-tapered with awn to 1.2-4 mm. Anthers 2.5-5 mm. Perigynia ascending to ascending-spreading, sometimes spreading, with deeply erose wings 0.7-1.7 mm wide, base cordate; beak ± straight, 6.5-9 mm from apex to achene, apex notched 0.7-1.5 mm adaxially. Achenes 3-4.5 × 2.3-3 mm. 2n = 74, 78.

Fruiting spring-summer. Sandy beaches along seacoasts, sounds, bays, and inlets, especially on dunes; 0 m; B.C.; Alaska, Oreg., Wash.; Asia [Japan, Russian Far East (Kamchatka) to n China].