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, (30–)45–80 cm × (0.8–)1.2–2.2 mm, glabrous.

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

blades and bracts without cross ribs.

flat to V-shaped, becoming trigonous apically, 15–30 cm × 0.5–3.2 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.

spikes oblong-cylindric, densely spicate, ± truncate at base, (9–)12–22 × (4–)6–12 mm;

rays 2–4(–5), (1.5–)2.5–6 cm;

bracts 4–6, longest erect or nearly so, larger ones flat or V-shaped, smaller capillary, trigonous, 3–24 cm × 0.4–3.6 mm;

rachilla ± deciduous, wings 0.2–0.4 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–)20–60, oblong to linear-lanceoloid, compressed-quadrangular, 3–9 × 2–3.4 mm;

floral scales deciduous, 2–4(–8), spreading, medially green, laterally stramineous, dull whitish or pale reddish brown, often red-dotted laterally, (3–)7–9-ribbed, ovate-lanceolate, (2–)2.2–2.8(–3) × (1–)1.2–1.8 mm, apex acute, weakly 3-dentate, mucro 0.2–0.6 mm, with apical tuft of crystalline prickles.

stamen 1;

anthers 0.5 mm;

styles 0.8–1.1 mm;

stigmas 0.5 mm.

anthers 0.4–0.9 mm;

styles 1–1.4 mm;

stigmas 1–1.6 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.

brown, ± stipitate, broadly ellipsoid, 1.4–1.5(–1.6) × 0.8–0.9 mm, 0.1 × 0.1–0.2 mm, apex ± truncate, apiculate, surfaces papillose.