Plants cespitose. Culms straight, (40–)65–110(–125) cm, tallest culms 65–125 cm. Leaves of flowering stems shorter than culms, to 28 cm × 1.8–3.8 mm; ligules on distal cauline leaves truncate or rounded. Inflorescences: peduncles of terminal staminate spikes (3–)10–60(–102) mm, 0.7–2.5 length of staminate spikes; bracts 5–25 cm × 1.2–2.5 mm, 0.5–1.3(–1.9) times as long as inflorescences; inner band of sheaths usually concave or truncate (occasionally convex). Spikes: proximal pistillate spikes 1–2(–3), distant, sessile or short-pedunculate, globose to ellipsoid or short-cylindric, 7–27 × 8–11 mm; terminal staminate spikes pedunculate, (9–)17–39 × 1.4–2.5 mm. Scales: pistillate scales pale yellowish green, inconspicuous among perigynia, 2.1–3.3 × 0.9–1.3 mm; staminate scales reddish brown to pale brown, narrowly obovate to narrowly oblong, 2.9–5.6 × 1.2–1.9 mm, margins wide, pale hyaline, apex obtuse to acute. Anthers 2.1–3.6 mm. Perigynia reflexed, yellow to yellowish green, (3.5–)3.9–5.2(–5.8) × 1.4–2.2 mm, apex abruptly narrowed; beak forming angle greater than 20° with body, 1.4–2.2 mm, sparsely scabrous or, occasionally, smooth. Achenes 1.4–1.9 × 1.2–1.5 mm.