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, (10–) 30–50(–80) cm × (0.8–)1–2 mm, glabrous or occasionally minutely scabridulous on distal angles.

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

blades and bracts without cross ribs.

3–7, M- or V-shaped, (10–)25–40(–55) cm × 2–5 mm, margins and midribs scabridulous or glabrous.

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.

spikes 3–6(–12), grayish to golden brown, loosely cylindric, (6–)10–20(–24) cm × (5–)8–11 mm;

rays 0 or 1–3, to 4 cm;

rachis glabrous;

bracts (3–)4–6(–8), horizontal to strongly reflexed, inversely W-shaped, (3–) 10–20(–30) cm × 1–5 mm;

rachilla deciduous, wings persistent, 0.3–0.5 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.

(10–)25–60(–100), spaced 1–2(–3) mm apart, broadly ellipsoid to oblong, ± terete, 2.4–3.6 × 0.8–1.2 mm;

distal spikelet spreading or ascending;

floral scales persistent, 1–2(–4), appressed, laterally golden brown to dull grayish white, frequently streaked with red, medially greenish, laterally 3–4-ribbed, medially 3-ribbed, oblong, 2.6–3.3 × 1.8–2.4 mm, apex broadly rounded.

stamen 1;

anthers 0.5 mm;

styles 0.8–1.1 mm;

stigmas 0.5 mm.

anthers 0.6–0.8 mm;

styles 0.8–1.2(–1.4) mm;

stigmas 1.4–2 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.

reddish brown to dark brown, stipitate, ellipsoid, (1.6–)1.8–2(–2.2) × (0.6–)0.7–0.9 mm, base cuneate to ± attenuate, apex ± acute to broadly rounded, surfaces finely papillose to essentially glabrous.