Flora of North America species comparison

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

basally cormlike, trigonous, 30–100 cm × 2–4 mm, glabrous.

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

V-shaped to flat, 20–70 cm × 3–8 mm, adaxial surface, margins minutely scabridulous.

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 loose, broadly ellipsoid to ovoid, 4–7 × 2–6 cm;

rays 6–13(–16), 4–25 cm, glabrous;

rachis 1.5–3 cm;

bracts 3–6, horizontal to ascending at 30°, flat, 5–35 cm × 2.5–6 mm;

rachilla persistent, wings 0.4–0.5 mm wide.

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.

(13–)20–60(–74), linear, ± terete, (11–)13–25(–28) × 1.2–1.5 mm;

distal spikelets spreading or ascending;

floral scales persistent, (2–)3–6, stramineous, red-purple striate, laterally 3–5-ribbed, ovate-lanceolate, 4.5–5.3 × 1.2–1.5 mm.

stamens 1–2;

anthers 0.8–1.4 mm;

styles 0.8–1 mm;

stigmas 0.6–0.8 mm.

anthers 1–1.5 mm;

styles 1.5 mm;

stigmas 1.5 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 to purplish brown, oblong-linear (5–6 times long as wide), 2.6–3 × 0.5–0.6 mm, base cuneate, apex obtuse, surfaces puncticulate.