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.

to 45 cm × 0.2–1 mm.

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

distal leaf sheaths persistent, firm, distally tightly sheathing, 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.

orbicular to ovoid, 1–9 × 1–4 mm, apex rounded to acute;

proximal scale without flower, not amplexicaulous;

floral scales to 125, 11–14 per mm of rachilla, tightly appressed, dark red-brown to stramineous, ovate to elliptic, 0.8–3 × 0.6–2(–2.3) mm, membranous to cartilaginous, apex rounded to acute.

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 (0–)4–8, typically 7, red-brown, rarely whitish, vestigial to much exceeding tubercle, typically equaling achene, spinules few to dense;

styles 2-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.

brown ripening to black, biconvex, orbicular to obpyriform, 0.5–1.1 × 0.3–0.7 mm, apex rarely constricted proximal to tubercle, very finely reticulate at 40X.

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

stramineous to whitish, umbonate to subconic, 0.2–0.4 × 0.2–0.5 mm, apex rounded to acute.

= 10.