Flora of North America species comparison

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

internodes and scales not evident.

terete, 45–100 cm × (3.2–)5–9.4 mm, soft to firm, sometimes septate-nodulose proximally, not distally, internally hollow with complete transverse septa, closer together near the spikelet, evident externally;

plants never forming filiform, flaccid culms.

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, membranous to thinly papery, apex acute to acuminate.

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

not proliferous, (20–)40–62 × 4–7 mm;

rachilla joints bearing prominent wing-like remnants of floral scales;

proximal scale empty, amplexicaulous, (3–)3.5–5 mm;

floral scales 115–220, 1–3 per mm of rachilla, stramineous to pale brown, usually with pale to dark brown submarginal band, midrib region sometimes greenish, obovate to broadly oblong, (4–)4.5–5 × 2.8–4 mm, cartilaginous, often membranous toward margins, margins broadly translucent, membranous, apex rounded to subacute.

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 6–8, stramineous, stout, flattened, subequal, exceeding achene, to 2.9 mm, coarsely spinulose;

anthers stramineous to reddish, 2.5–5 mm;

styles 2-fid or 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.

stramineous to golden-yellow or reddish brown or gray, obovoid to obpyriform, biconvex or nearly plano-convex, often with abaxial longitudinal ridge, 1.4–1.8(–2) × 1.1–1.4 mm, markedly sculptured at 10–15X, each face with 23–37 rows of transversely elongated cells, the longitudinal walls separating the cells often prominent, apex with short neck 0.7–0.8 mm wide.

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.

dark brown, lamelliform, slightly higher than wide, 0.7–1.1 × 0.5–0.7 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.