Flora of North America species comparison

50–150 cm × 4–8 mm.

sheaths reaching beyond middle of culm, fronts usually convex, papery at mouth, veins reaching margin, or occasionally membranous with veins diverging proximal to apex leaving triangular, veinless area;

widest blade 4–12 mm wide.

simply branched with 1 or not more than 1/2 of spikelets solitary or in clusters of 2(–3) on 1–7 rays, rays not exceeding 7 cm;

involucral bracts that surpass inflorescence 2–4, widest bract 2–7 mm wide.

(1–)5–25, broadly ovoid to rarely lanceoloid, 10–30 × 6–10 mm, base usually truncate;

scales usually tightly imbricate, medium to dark orange-brown, lineolate-spotted at 15X, usually 6–9 × 3–4 mm, papery and nearly opaque, rarely membranous, apex 2-fid, 1 mm deep, awn very stout, 2–3 × 0.5 mm at base.

perianth bristles not persistent on shed achene or 1–2 weakly attached to shed achene, dark red-brown, 1/2 achene length;

anthers brownish orange, 1.5–2.5 mm;

styles (2–)3-fid.

dark to medium brown, obovoid, compressed-trigonous with broadly rounded abaxial angle or sometimes biconvex, 2.7–3.5 × 1.8–2.8 mm, apex truncate to broadly rounded, beak 0.1–0.3 mm, surface glossy, exocarp cells evident at 10–20X; in achene cross section exocarp 2 times thicker than mesocarp and its cells greatly enlarged, 3 times or more deeper than wide;

achene specific gravity much less than water.