Flora of North America species comparison

yellow-brown to dark brown at base, 15–60 cm.

dark brown to chestnut at base, surrounded by remains of previous year’s leaf bases, but not conspicuously fibrillose; flowering stems 60–180 cm × 2–2.5 mm, much longer than leaves at maturity, glabrous.

sheaths hispidulous;

blades green, widest blades (3–)3.4–5.4(–6.5) mm wide, glabrous abaxially or sparsely hispidulous on midrib.

sheaths glabrous, ivory to brown on back, dark chestnut-hyaline on front, sometimes finely red dotted near apex;

blades rigid, flat distally but often keeled or channeled near base, margins revolute, 4–8 mm wide, finely retrorse-scabrous adaxially, margins and abaxial midribs also sometimes finely scabrous.

0.19–0.48 of culm height;

peduncles of lateral spikes smooth or barely scaberulous;

peduncles of terminal spikes (4.2–)7.5–37(–43) mm, much exceeding lateral spikes;

proximal bract with sheath tight, abaxially scabrous, sheath front apex convex, elongated (0.6–)1.6–4.9(–6.6) mm beyond apex;

ligules 3.3–5 mm;

distal bract usually much exceeding terminal spike.

peduncles of lateral spikes slender, to 10 mm, finely scabrous;

peduncle of terminal spike scabrous;

proximal bracts shorter than inflorescences;

sheaths 9–100 mm;

blades 2–3.5 mm wide.

3–5, separate or distal 2–4 spikes overlapping;

lateral spikes pistillate, with 2–7 perigynia, 6–29 × 3.8–6.8 mm, ratio of spike length (in mm) to flower number = 3.5–4.8;

longest terminal spikes 14–34(–42) × 1.3–3(–3.5) mm.

distichously imbricate, 52–59-veined, unwrinkled, obovoid or narrowly obovoid, obtusely triangular in cross section, (4.5–)4.6–5.6(–6.2) × 1.9–2.2(–2.3) mm, (2.1–)2.3–2.8(–3) times as long as wide, dull, base gradually tapered, apex abruptly contracted;

beak excurved, (0.5–)0.8–1.3 mm.

green, usually red dotted, strongly 2-ribbed, 12–20-veined, loosely enveloping achene, lance-ellipsoid, 5–8 × 1.4–2.7 mm, membranous, base with short stipe, apex tapering to beak, shortly and evenly pubescent;

beak bidentate, margins serrulate.

obovoid-ellipsoid, 3.2–3.9(–4.2) × (1.6–)1.8–2.1 mm, tightly enveloped by perigynia;

stipe bent 45–70°, 0.4–0.6 mm;

beak bent more than 90°, 0.3–0.5 mm.

sessile, 3–4 × 1.4–2.2 mm.

scales (4.1–)5.6–9.4(–11.6) × 1.6–2.6(–3.3) mm, margins whitish, denticulate, apex with awn 1.1–6.8 mm.

scales suffused with chestnut except for hyaline margins and green midrib, ovate to oblong, shorter than mature perigynia, apex acute, sometimes with scabrous awn to 1 mm, glabrous.

scales 5.2–6.9 × 1.5–1.7 mm.

3.4–4.2 mm.

spikes 6–15, 1–3 per node;

proximal spikes well separated (except those at same node), erect or arching at maturity, pistillate with 15–45 perigynia attached less than 1 mm apart, cylindric, 2.5–8 × 4–6 mm;

distal spikes staminate or androgynous, erect, crowded near apex, sessile or short-pedunculate.

spike staminate, often crowded with other staminate or predominantly lateral staminate spikes, 20–80 × 2.5–7 mm.