Flora of North America species comparison

usually present, caudexlike, ascending, 1 mm thick, hidden by crowded culms;

internodes and scales not evident.

subterete, often with to 6 prominent ridges when dry, sulcate, 10–30 cm × 0.3–0.5 mm, firm to rigid, spongy.

sometimes spirally twisted, usually minutely red-spotted at 30X, acutely triangular or sometimes elliptic, 15–70 cm × 0.3–0.5(–1) mm, soft (to firm), often minutely granular at 10X.

distal leaf sheaths persistent, not splitting, proximally brown, red, or stramineous, distally stramineous, green or reddish, papery, apex sometimes reddish, obtuse, rarely callose, tooth absent.

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

ovoid, 3–8 × 2–3 mm, apex acute to obtuse;

proximal scale amplexicaulous, entire;

subproximal scale with flower;

floral scales spreading in fruit, 8–30, 4–5 per mm of rachilla, dark brown to blackish, midrib regions often stramineous or greenish, ovate to lanceolate, 2–3 × 1.5 mm, apex entire, acute, often carinate in distal part of spikelet.

basal spikelets absent; never proliferous, ovoid to lanceoloid or ellipsoid, terete, 4–12 × 2–4 mm, apex acute;

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

subproximal scale often empty;

floral scales spiraled, 10–25, 5–6 per mm of rachilla, pale orange-brown, midrib regions broadly pale green to colorless, broadly ovate, 2–2.5(–3.5) × 1.5–2 mm, central area and often flanks papery to cartilaginous or sometimes membranous, midrib evident, apex subacute (to rounded).

perianth bristles 3–6, whitish to stramineous, stout to slender, often unequal, from rudimentary to 1/2 of achene length;

stamens 3;

anthers dark yellow to brown, 0.9–1.4 mm;

styles 3-fid.

perianth bristles 4–6, bright brown, stout, equaling to slightly exceeding tubercle;

spinules dense, retrorse, sharply acute;

stamens 3;

anthers 0.5–0.9 mm;

styles 3-fid.

falling with scales, stramineous, rarely dark brown, ovoid to obpyriform, slightly to greatly compressed-trigonous, rarely thickly lenticular, angles prominent or abaxial angle obscure, 0.9–1.2 × 0.65–0.8 mm, apex narrowly to broadly truncate, neck short, often compressed more than body, at 20–30X finely rugulose with more than 20 horizontal ridges in a vertical series or reticulate or cancellate.

medium brown or yellowish or greenish, obpyriform, obtusely (often obscurely) compressed trigonous, angles evident, 1.2–1.7(–2.4) × 0.9–1.2(–2.2) mm, apex constricted proximal to tubercle, coarsely cancellate at 10X, each face with 8–10 longitudinal rows of distinctly depressed, enlarged cells.

whitish to brown, pyramidal, lower than wide, often 3-lobed as viewed from the top, 0.1–0.3 × 0.4–0.65 mm.

brown to greenish (or bone-white), pyramidal, trigonous or cross section plano-convex, 0.3–0.7(–1) × 0.3–0.6(–0.9) mm, distinctly shorter or narrower than achene, apex acute, often acuminate.