Flora of North America species comparison

present or not, caudexlike, ascending, 1 mm thick;

internodes and scales hidden by crowded culms, not evident.

erect, not spirally twisted, not contracted near spikelet, when dry usually with several blunt to acute ridges and sulcate, subterete to slightly compressed, to 2 times wider than thick, 5–35 cm × 0.2–0.5(–1.2) mm, soft to hard;

culm tufts often proximally bulbous (if bulbous then tunicated by papery-fibrous scales).

elliptic or sometimes circular, with several rounded ridges and sulcate when dry, 15–75 cm × 0.3(–1.5) mm, firm, minutely granular at 10X.

distal leaf sheaths stramineous to brown or reddish proximally, green to stramineous or brown distally, membranous to papery, apex often reddish, subtruncate to acute.

distal leaf sheaths persistent; stramineous to green, often minutely red-spotted, papery to membranous, apex subacute to narrowly acute, often with tooth-like callus.

3–8 × 1.5–4 mm;

proximal scale with a flower, seldom empty, 2–5 mm, 1/2 or more as long as spikelet;

floral scales 3–10 per spikelet, 2.5–6 × 1.5–2.5 mm.

basal spikelets absent; never proliferous, ovoid, terete, 5–15 × 2.5–4 mm, apex acute;

proximal scale empty, deciduous, clasping 1/2 of culm, similar to floral scales;

subproximal scale often empty;

floral scales spiraled, 10–30, 5–6 per mm of rachilla, pale orange-brown, midribs green, broadly ovate, 2.5–4 × 1.5–2.5 mm, central area and often flanks papery to cartilaginous (or membranous), midrib evident, apex broadly rounded to obtuse.

perianth bristles (0–)3–6, often unequal, rudimentary to equaling tubercle, stout to slender, spinules dense to apparently absent;

anthers 1.5–2.7(–3.5) mm.

perianth bristles 5–6, bright brown, stout, slightly shorter than to equaling tubercle;

spinules rarely absent, dense, variably from divaricate to antrorse, very short, and blunt to acute, to often much longer and retrorse, sharply acute;

stamens 2–3;

anthers 0.5–1 mm;

styles 3-fid.

stramineous to medium brown or gray-brown, equilaterally trigonous to compressed-trigonous, rarely some biconvex, obpyriform (to obovoid), 1.6–2.3 × 0.7–1.3 mm, beak variable.

medium brown, obovoid to obpyriform, compressed (often obscurely) trigonous, angles evident, 0.9–1.7 × 0.8–2 mm;

apex often constricted proximal to tubercle, very coarsely cancellate at 10X, each face with 8–10 longitudinal rows of large depressions.

rarely absent, 0.3–0.4 × 0.2–0.3 mm.

bone-white to pale orange-brown, often red-spotted, subpyramidal, cross section plano-convex, 0.9–1.7(–2.4) × 0.7–1.2–2(–2.2) mm, at least as high and wide as achene, spongy, apex rounded, often with an abaxial acute projection.