Flora of North America species comparison

15–120 cm;

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

3–130 cm.

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 adaxially red dotted and usually copper colored at mouth, concave at mouth, prolonged 1–4(–6) mm beyond base of blade;

ligules 4.1–13.7 mm;

foliage leaf blades 10–90 cm × 2.5–5(–6) mm.

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.

bisexual or, occasionally, nearly or wholly unisexual, flexuous and interrupted, proximal 0–5 branches (or spikes) often separated, decompound, (2–)3–8 × 1–2 cm;

basal branch (when present) with 5–21 spikes (or ca. 40 spikes in very condensed inflorescences);

proximal internode 4–12 mm.

(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.

spreading, straw colored to light or dark brown, strongly 7–11-veined abaxially, with median lengthwise groove near base, with or without membranous flap toward apex, lance-ovate (body widely ovate to oblate) in outline, plano- to biconvex, 2.4–3 × 1.3–1.8 mm, shiny;

beak 1–1.3 mm.

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

broadly ellipsoid to broadly trullate-ovate or obovate in outline, 1.4–1.6 × 0.7–1.1 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 straw colored or reddish brown, 2.5–3.4 × 1.5–2.1 mm, as wide as and equaling perigynia.

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