Flora of North America species comparison

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.

erect to ascending, ± quadrangular to pentagonal or broadly elliptic, sometimes sulcate, (1.9–)4.2–8.6 cm (extraterritorial plants to 12 cm) × 0.2–0.4 mm, soft.

distal leaf sheaths persistent, membranous to thinly papery, apex acute to acuminate.

distal leaf sheaths persistent or fugaceous, pale brown or red-brown sometimes spotted or streaked red-brown, translucent, membranous, apex acute.

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, ellipsoid or obovoid, laterally compressed when young, but terete at maturity, 1.9–4 × 1–3 mm, apex acute, proximal scale empty, deciduous, amplexicaulous or nearly so, similar to floral scales, 0.6–2.5 × 0.8–1.2 mm, midrib sometimes slightly prolonged beyond lamina;

subproximal scale with a flower;

floral scales distichous or spirodistichous, (2–) 4–10, 3–5 per mm of rachilla, pale brown, spotted or streaked red-brown, ovate or elliptic, 1.7–2.2 × 0.4–0.7 mm, membranous, midrib green, spotted red-brown, prominent, apex 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 6, red-brown, equaling to much exceeding tubercle;

spinules sparse, retrorse, sharply acute;

stamens 3;

anthers 0.5–0.7 × 0.1 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.

whitish or pale brown, circular in outline, ellipsoid, or obovoid, trigonous, angles prominent, 0.6–0.8 × 0.5–0.6(–0.7) mm, apex constricted proximal to tubercle, smooth.

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

white or red-brown, pyramidal, trigonous, 0.2–0.4 × 0.3–0.4 mm.