Flora of North America species comparison

15–120 cm;

vegetative culms few, inconspicuous, usually fewer than 15 leaves, not strikingly 3-ranked.

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 adaxially white-hyaline, summits U-shaped or sometimes prolonged to 2 mm beyond collar and rounded, smooth;

distal ligules 2.2–3.5 mm;

blades 3–5 per fertile culm, 12–30 cm × 1.5–3.5 mm.

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.

open, brown, (1.3–)2.5–5(–6.5) cm × 5–18 mm;

proximal internode (3–)6–13(–23) mm; 2d internode 2–12 mm;

proximal bracts scalelike or bristlelike, shorter than inflorescences.

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–)4–7, 5–7 on larger culms, distant, distinct, ovoid to ellipsoid, 7–17(–24) × 4–8(–12) mm, base attenuate or rarely rounded, apex acute to rounded;

terminal spike usually with conspicuous staminate base.

(10–)15–40(–45) per spike, ascending-spreading, green or reddish brown, veinless or faintly and irregularly 1–5-veined adaxially, orbiculate or broadly ovate, plano-convex, (2.6–)3.4–4.8(–5.2) × (2–)2.3–3.2 mm, 0.5–0.6 mm thick, 1.2–1.8 times as long as wide, nearly leathery, margin flat, including wing 0.3–0.8 mm wide, ciliate-serrulate at least distally, smooth;

beak pale green or brown at tip, flat, ± ciliate-serrulate, abaxial suture with gold or reddish brown-hyaline margin, distance from beak tip to achene 1.5–2.4 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.

orbiculate to broadly ovate, 1.5–2.2 × 1.3–1.8 mm, 0.5–0.6 mm thick.

sessile, 3–4 × 1.4–2.2 mm.

scales white-hyaline, tinged reddish brown, usually with whitish, pale gold, or green midstripe, broadly lanceolate to narrowly ovate, 2.6–4.3 mm, as long as to 0.7–0.9 mm shorter than perignyium beaks, narrower than perigynia, margins thin, sometimes involute, apex mostly acute.

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.

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.

= 48, 52, 56, 60, 64, 68.