Culms round to round-trigonous, 5-26 cm. Leaf blades 6-25 cm, 0.3-0.5 mm wide near base. Spike 7-20 × 3.5-6 mm, staminate portion 4-12 mm. Longest pistillate scales 2.2-3.3(-4) × 1.8-2.5(-4) mm, often shorter than perigynia. Perigynia obovate or elliptic, (1.9-)2.1-2.6(-3) × 1.3-1.7(-1.9) mm, sometimes ruptured by achene; beak 0-0.2(-0.3) mm. Achenes 1.5-2.3 × (1.1-)1.3-1.5 mm.