Flora of North America species comparison

roundly trigonous, basally with dark fibrous remnants of old leaf sheaths, (0.5–)4–30 cm × 0.4 –1.1 mm, glabrous.

roundly trigonous, 10–50 cm × 0.9–2.4 mm.

1–5, flat, involute toward apex, 3–18 cm × 1–2.5(–3) mm.

adaxial face concave, becoming flat to trigonous apically, 10–46 cm × 1.5–4 mm, margins involute.

heads hemispheric to spheric, (3–)6–15(–24) mm diam.;

rays absent;

bracts 2–5, horizontal to reflexed, parallel to culm, 1–13 cm × 1–3 mm, margins and keel sparsely minutely scabridulous distally.

spikes ovoid, 1–5.5 cm wide;

rays usually 3–6, 0.5–5 cm, glabrous;

sometimes absent in small plants;

if absent, inflorescence a congested head of spikelets 1–3.5 cm diam.; 2d order rays 0–3, 1–3 cm;

bracts 3–5, vertical to ascending at 45°, 2.5–25 cm × 1.2–4 mm, margins involute; 2d order bracts 0–2, 5–20 mm;

rachilla persistent, wingless.

(5–)20–60(–100), whitish to greenish or brownish, ovoid to oblong-lanceoloid, compressed, 3–7 × 2–4 mm;

floral scales (8–)10–12(–24), laterally milky white (infrequently yellowish, pale greenish, brown, or bronze-white), medially green or white, laterally ribless, medially 3-ribbed, ovate to ovate-lanceolate, 1.6–3(–3.4) × 0.8–1.3 mm, apex mucronate to acuminate.

5–24, greenish yellow to golden brown, oblong to linear-lanceoloid, quadrangular, strongly compressed, 7–20(–30) × 2.5–4(–6) mm;

floral scales 10–20(–40), spreading, pale green to stramineous, laterally 2–3-ribbed, ovate-lanceolate, 3.1–4 × 1.5–2.4 mm, apex with mucro 0.2–0.8 mm.

stamens 3;

anthers linear, (0.4–)0.6–0.8(–1.1) mm, connective not prolonged;

styles 0.8–1.8 mm;

stigmas (0.5–)1–1.5(–2) mm.

anthers 0.6–0.8 mm;

styles 0.8–1.6 mm;

stigmas 1–1.4 mm.

brown to blackish, trigonous, broadly obovoid, 0.5–1 × 0.3–0.75 mm, base slightly stipelike, ± cuneate to rounded, apex apiculate, papillose.

light to dark brown, rarely somewhat reddish, stipitate, ellipsoid, 2–2.4 × 0.5–0.8 mm, base cuneate, stipe whitish, spongy, 0.2–0.3 × 0.2–0.4 mm, apex acute, persistent style forming beak 0.5–1.2 mm, surfaces glabrous or finely papillose.