Flora of North America species comparison

2–6, trigonous, (10–)35–80 cm × 0.5–2(–4) mm, scabridulous with retrorse prickles (infrequently glabrous or rarely also with extrorse prickles).

trigonous, 20–36 cm × 0.5–1 mm.

3–9, V-shaped, (12–)25–45(–65) cm × 2–10 mm;

blades and bracts without cross ribs.

flat, 4–22 cm × 1–2 mm.

heads umbellate, 10–20(–30) mm diam.;

rays 4–12, 1–6 cm, minutely scabridulous with retrorse prickles; 2d order rays often present, 1–2(–3) cm; 3d order rays rarely present, 0.5–1.5 cm;

bracts 3–8, approximately horizontal to ascending at 30°, V-shaped to flat, 2–15(–34) cm × 1–4(–5) mm.

a single loose cluster of spikelets;

rays 0–(1–2), if present, to 4 cm;

bracts 2–3, ascending, 1–8 cm × 0.7–1 mm;

rachilla with wings 0.6 mm wide.

(6–)15–40(–65), greenish white, linear to linear-oblong, (3–)4–12(–15) × 1.5–2.5 mm;

floral scales 10–50(–65), laterally pale yellow, light brown, or reddish brown, 2-keeled, medially 3-ribbed, lanceolate, 1–1.5 × 0.8–0.9 mm, distinctly reticulate, often scabridulous near apex.

2–8, linear, terete, 6–20 × 0.7–1 mm;

floral scales 6–10, medially green, laterally brown, medially faintly 3-ribbed, laterally faintly 3–5-ribbed, ovate, 2.5–3 × 2 mm.

stamen 1;

anthers 0.5 mm;

styles 0.8–1.1 mm;

stigmas 0.5 mm.

anthers 1 mm;

styles 0.5 mm;

stigmas 1 mm.

brown to reddish brown, slightly stipitate, narrowly ellipsoid, 0.7–0.9 × 0.2–0.4 mm, apex apiculate, surfaces papillate or obscurely reticulate to rugulose.

black, sessile, obovoid, 2 × 0.8 mm, apex scarcely apiculate, surfaces puncticulate.