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 to 16 blunt ridges when dry, 25–80 cm × 0.5–1.5 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 dark red, distally red to stramineous or green, often callose, thinly papery (to membranous), apex dark red-brown, obtuse to subtruncate, tooth sometimes present on some culms, to 0.3 mm.

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, 5–23 × 2–3(–4) mm, apex acute (to obtuse);

proximal scale amplexicaulous, entire;

subproximal scale with flower;

floral scales often spreading in fruit, 10–60, 3–4 per mm of rachilla, medium brown, rarely red-brown, midrib regions mostly stramineous to green, in proximal part of spikelet ovate, in distal part lanceolate, 2.5–3.5 × 1.7 mm, entire, apex acute to rarely obtuse, often 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 2–4(–5), brown, slender to stout, usually very unequal, rudimentary to equaling achene;

stamens 3;

anthers brown, 1.5–2 mm;

styles 2-fid, sometimes some 3-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 stramineous, obovoid to obpyriform, all biconvex or some (very rarely all) compressedtrigonous, angles obscure, 1–1.5 × 0.9–1.25 mm, apex rounded, neck absent (to very short), finely rugulose at 10–20X, with 20 or more horizontal ridges in vertical series and/or finely cancellate at 10–30X.

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

brown or proximally whitish, pyramidal, depressed, rarely some as high as wide, 0.15–0.3(–0.5) × (0.3–)0.4–0.6 mm.

= 44, 45, 46.