Flora of North America species comparison

present, caudexlike, mostly concealed by crowded culms, vertical or ascending, 2 mm thick;

internodes very short, scales disintegrating to fibers, 4 mm, papery.

erect to ascending or arching, acutely quadrangular, deeply sulcate, 7–50 cm × 0.3–0.5 mm, smooth, firm.

terete, often with some blunt ridges when dry, (5–)10–60 cm × 0.2–1.5 mm, firm, internally spongy.

distal leaf sheaths persistent, proximally brown or reddish, distally stramineous to green, thickly membranous, apex acute or subacute.

distal leaf sheaths persistent, not splitting, proximally red, distally stramineous to green, often callose, thinly papery to thickly membranous, apex often dark red-brown, obtuse to subacute, tooth absent.

basal spikelets absent; often proliferous, ovoid, terete, 3–10 × 2–3 mm, apex acute;

proximal scale empty, amplexicaulous, similar to floral scales;

subproximal scale with a flower;

floral scales spiraled, 8–15, 4 per mm of rachilla, orange-brown, midrib region broadly stramineous or like flanks, ovate, 2–3 × 1.2–2 mm, membranous, midrib evident to prominent, apex acute (to rounded).

ovoid to lanceoloid, 5–10 × 2–3(–4) mm, apex acute;

proximal scale amplexicaulous, entire;

subproximal scale with flower;

floral scales often spreading in fruit, 10–20, 3–4 per mm of rachilla, brown to often red-brown, midrib regions mostly stramineous to green, broadly ovate, 3–4 × 1.8–2.5 mm, entire, apex acute to obtuse, often some carinate in distal part of spikelet.

perianth bristles 6 or fewer, stramineous, unequal, some or most equaling achene, spinules obscure, sparse, retrorse, sharply acute.

perianth bristles 0–4(–5), light brown to stramineous, stout, usually unequal, rudimentary to equaling achene;

stamens 3;

anthers dark yellow to stramineous, 1.2–2 mm;

styles 2-fid.

3;

anthers 1.2–1.5 mm.

3-fid.

stramineous, broadly obpyriform, equilaterally trigonous, angles evident, blunt, 0.9–1.1 × 0.7–0.9 mm, apex nearly truncate, smooth or obscurely papillose or rugulose at 20X.

not persistent, dark yellow or medium or dark brown, ellipsoid, obovoid, or obpyriform, biconvex, angles obscure, 1.3–1.8 × 1–1.4 mm, apex rounded, neck absent or short, smooth at 30X, or sometimes finely rugulose at 10–20X with 20 or more horizontal ridges in vertical series.

stramineous, pyramidal, trigonous, usually acute, proximally trilobed, the lobes decurrent on achene, 0.5–0.9 × 0.7–0.9 mm.

brown to whitish, pyramidal, much higher than wide to slightly depressed, sometimes spongy and with vertical rows of depressions, 0.4–0.8 × 0.3–0.8 mm.