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).

roundly trigonous, 300–500 cm × 15–45 mm, glabrous.

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

blades and bracts without cross ribs.

bladeless.

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 loosely cylindric, 10–20 × 6–10 mm;

rays 40–100, drooping or arching, slender, 10–30 cm; 2d order rays 8–20 cm;

bracts 4–10, ± erect, V-shaped, 3–8 cm × 4–15 mm; 2d order bracts 2–5, (1.5–)4–16 cm × 0.5–2 mm;

rachilla persistent, separating laterally, remaining firmly attached basally, wings 0.3–0.4 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.

6–30, slightly compressed, linear, ± quadrangular, 6–10 × 0.8–1 mm;

floral scales 6–16, reddish beside 5-ribbed green medial part, white to hyaline near margins, ovate-elliptic, 1.8–2.2 × 1.2–1.5 mm, apex acute to obtuse.

stamen 1;

anthers 0.5 mm;

styles 0.8–1.1 mm;

stigmas 0.5 mm.

anthers 0.8–1 mm (connectives prolonged beyond anther as red subulate appendage 0.2–0.5 mm, apex usually setose);

styles 0.2–0.4 mm;

stigmas 0.8–1.2 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.

pale brown, sessile, oblong, 0.8–1 × 0.4 mm, apex scarcely apiculate, surfaces puncticulate.