Flora of North America species comparison

often arching, sometimes spotted or streaked red-brown, quadrangular or broadly elliptic, sulcate or not, 0.5–25(–30) cm × 0.1–0.4 mm, soft.

terete or cross section elliptic (or rectangular), usually with to 8 blunt ridges when dry, 10–50 cm × 0.2–0.7(–1) mm, soft to firm, spongy.

distal leaf sheaths persistent or disintegrating, stramineous, green, red-brown, or spotted or streaked red-brown, membranous, translucent, apex obtuse or acute.

distal leaf sheaths persistent, not splitting, mostly proximally dark red, distally red to brown or green, thinly papery to thickly membranous, apex usually redbrown, subtruncate to obtuse or subacute, callose, tooth often present on most or all culms, to 1 mm.

basal spikelets usually present, pistillate; often proliferous, ovoid, ellipsoid, or linear, clearly laterally compressed, 2.3–6.9 × 0.5–2 mm, apex acute, proximal scale empty, amplexicaulous, similar to floral scales (midribs sometimes more prominent and sometimes slightly prolonged beyond lamina);

subproximal scale with a flower;

floral scales clearly distichous, 3–9, 3–4 per mm of rachilla, yellowish, pale brown, or red-brown, spotted, streaked, or mottled red-brown, narrowly ovate to oblong, (1.5–)2–5 × 0.4–0.6(–1.2) mm, membranous, apex rounded, obtuse or rarely acute, midribs keeled.

narrowly lanceoloid (to narrowly cylindric), 3–20 × 1.5–2.5 mm, apex acute;

proximal scale amplexicaulous, entire;

subproximal scale empty or with flower;

floral scales appressed or spreading in fruit, 15–40, 3–4 per mm of rachilla, orange brown, midrib regions often greenish, ovate, 2–3 × 1 mm, apex entire, rounded to obtuse in proximal part of spikelet, acute in distal part, carinate, at least in distal part of spikelet.

perianth bristles 3–7, incurved, colorless, white, or red-brown, shorter than or equaling achene;

spinules sparse, retrorse, sharply acute;

stamens 3;

anthers 1.4–2.2 mm;

styles 3-fid.

perianth bristles 3–7, rarely apparently absent, stramineous to whitish, slender to stout, often unequal, rudimentary to slightly exceeding tubercle;

stamens 3;

anthers yellow to stramineous, 1.1–2 mm;

styles 3-fid, 0.3–0.4 × 0.2–0.3 mm.

whitish or greenish, spotted dark green, obovoid, trigonous, angles prominent, 0.6–0.9 × 0.4–0.6 mm, apex constricted proximal to tubercle, smooth to finely cancellate at 10–20X.

falling with scales, yellow-brown or dark brown, ellipsoid or obovoid to obpyriform, compressed-trigonous, angles evident to obscure, rarely prominent, 0.8–1.4 × 0.5–0.7 mm, neck absent to long, smooth or sometimes minutely cancellate at 20–30X.

pale to red-brown, pyramidal, trigonous, 0.2–0.3(–0.4) × 0.2–0.5 mm.

whitish, pyramidal, often higher than wide, 0.3–0.4 × 0.25–0.35 mm.

= 10.