Flora of North America species comparison

trigonous, (20–)60–70(–100) cm × 2.4–6.9 mm, scabrid on angles.

trigonous, (4–)10–50(–130) cm × (0.5–)1–4 mm.

4–12, flat to V-shaped, with readily visible cross ribs especially on abaxial surface, 20–50 cm × 3–14 mm.

flanged V- or inversely W-shaped, 5–30(–60) cm × 4–12 mm.

heads digitate to hemispheric, 1–3.5 cm diam.;

rays 6–12, 1–9(–14) cm; 2d order rays often present, (0.5–)1–3 cm; 3d order rays occasionally present, 5–12 mm;

bracts 4–8, horizontal to ascending at 30°, with prominent cross ribs,V-shaped, (1.5–)3–50(–75) cm × 0.5–13 mm; 2d order bracts 3–10 × 1–2 mm.

spikes 1–5(–12), loosely to densely cylindric, ovoid, or ± pyramidal, 10–20(–40) × (8–)10–30(–35) mm;

rays (0–2)6–9(–12), 2–8(–13) cm;

if rays absent, infloresence a single dense, capitate cluster of closely imbricate spikes;

bracts (4–)5–8(–10), horizontal to ascending at 30–60°, (3–)10–25(–55) cm × 1–14 mm;

rachilla hyaline or thickened bronze, carmine, or yellowish, wings clasping achene.

10–40(–50), oblong to linear-lanceoloid, 5–18 × 2–3.2 mm;

floral scales 10–40, pale grayish brown, or greenish, proximally greenish or brownish, oblanceolate, 2-keeled, weakly to distinctly 1-ribbed, proximal half 2-ribbed, (1.3–)1.5–2(–2.4) × 0.9–1.4 mm, apex acute (sometimes mucronulate), apically glabrous, occasionally scabridulous.

(10–)20–60(–100), linear-oblong to narrowly linear, cylindric to slightly flattened (when scale tips spreading), (5–)8–15(–38) × 0.8–1.3(–1.9) mm;

floral scales (4–)8–12–(30), medially green, laterally reddish to stramineous to shiny brown or beige, medially 2–5-ribbed, laterally 1–3-ribbed, ovate to elliptic, (2–)2.2–2.8(–3.2) × (1.2–)1.4–1.6(–1.8) mm, apex entire or emarginate with mucro to 0.3 mm.

stamens 1–2;

anthers 0.8–1.4 mm;

styles 0.8–1 mm;

stigmas 0.6–0.8 mm.

anthers (0.2–)0.3–0.4(–0.7) mm;

styles 0.4–0.7(–1) mm;

stigmas (1–)1.5–3 mm.

brown, slightly to distinctly stipitate, ellipsoid (2.7–4.1 times as long as wide), (0.9–)1.2–1.5 × 0.3–0.4 mm, apical beak 0.1–0.5 mm, surfaces glabrous.

brown, reddish brown, or black, stipitate, narrowly ellipsoid to oblong (rarely obovoid-oblong), (1–)1.2–1.5(–1.9) × 0.5–0.6(–0.75) mm, stipe 0.1–0.2 mm, apex acute to barely obtuse, surfaces finely papillose.