Flora of North America species comparison

fertile ones upright or nearly so;

nodes without axillary bulblets.

fertile ones lax, reclining, inflorescences lopping over to (or nearly to) ground;

nodes frequently with axillary bulblets.

5–10 per culm;

sheaths of proximal leaves green or whitish;

proximal sheaths and blades with septa many, conspicuous or not;

blades 20–55 cm × 8–16 mm.

10–18 per culm;

proximal leaf sheaths green or brownish;

proximal sheaths and blades with septa few, inconspicuous;

blades 16–55 cm × 4–8 mm.

terminal, rarely also with 1 lateral inflorescence from distal leaf axil;

rays ascending or divergent (commonly both in same inflorescence), smooth throughout or scabrous at distal end, rays without axillary bulblets;

bases of involucral bracts green or margins brown, not glutinous.

terminal;

rays divergent, proximal rays smooth, pedicels and distal rays scabrous, rays often bearing axillary bulblets;

bases of involucral bracts green or brownish, not glutinous.

aggregated in a few dense clusters of 12–130 (largest cluster with 40–50+), spikelets sessile, narrowly ovoid, 4–5 × 1.8–2.3 mm;

scales black or brownish black with pale midribs, elliptic to ovate, 1.6–2.8 mm, ending in terete or flat awn 0.4–0.6(–1.2) mm.

in open cymes, central spikelet of each cyme sessile, others long-pedicellate, spikelets cylindric to narrowly ovoid, 4–14 × 1–2 mm;

scales light brown to reddish with broad green midribs, broadly ovate or elliptic, 1.2–1.8 mm, apex rounded to obtuse, apiculate, or sometimes short-mucronate, apiculus or mucro (if present) to 0.1 mm.

perianth bristles persistent, 6, rather stout, straight or curved, longest bristles equaling achene, with retrorse, thin-walled, round-tipped teeth in distal 0.3–0.5, enclosed within scales;

styles 3-fid.

perianth bristles persistent, 6, stout, contorted, equaling or longer than achene, not projecting beyond it, with delicate, round-tipped, retrorse teeth in distal 1/2, enclosed within scales;

styles 3-fid.

pale brown or almost white, oblong-elliptic to elliptic or obovate in outline, plumply trigonous or plano-convex, 0.8–1.2 × 0.4–0.6 mm.

off-white to yellowish brown, elliptic-obovate in outline, strongly trigonous with very strong angles and concave sides, 0.8–1 × 0.6–0.8 mm.

= 56.

= 28.