Flora of North America species comparison

terete, often with some blunt ridges when dry, (5–)10–60 cm × 0.2–1.5 mm, firm, internally spongy.

often ascending or arching, quadrangular or broadly elliptic, 2–40 cm × 0.1–0.4(–0.6) mm, soft.

distal leaf sheaths persistent, not splitting, proximally red, distally stramineous to green, often callose, thinly papery to thickly membranous, apex often dark red-brown, obtuse to subacute, tooth absent.

distal leaf sheaths persistent or disintegrating, pale brown, green or red-brown, streaked or mottled red-brown or purple, translucent, membranous, apex narrowly acute.

ovoid to lanceoloid, 5–10 × 2–3(–4) mm, apex acute;

proximal scale amplexicaulous, entire;

subproximal scale with flower;

floral scales often spreading in fruit, 10–20, 3–4 per mm of rachilla, brown to often red-brown, midrib regions mostly stramineous to green, broadly ovate, 3–4 × 1.8–2.5 mm, entire, apex acute to obtuse, often some carinate in distal part of spikelet.

basal spikelets absent; often proliferous, ovoid to ellipsoid or lanceoloid, terete, 2–10.7 × 1–2 mm, apex acute;

proximal scale empty, persistent, amplexicaulous, dissimilar to floral scales, often longer, often resembling an involucral bract, ovate to lanceolate, midrib markedly thickened and broad and often prolonged beyond lamina;

subproximal scale with flower;

floral scales spiraled, colorless, whitish, or pale brown, streaked or mottled red-brown or purple, midribs green and red-brown or green and purple, ovate to elliptic, 0.8–1.5 × 0.4–0.8 mm, membranous, midrib obscure to prominent.

perianth bristles 0–4(–5), light brown to stramineous, stout, usually unequal, rudimentary to equaling achene;

stamens 3;

anthers dark yellow to stramineous, 1.2–2 mm;

styles 2-fid.

perianth bristles present or sometimes apparently absent;

stamens 3;

anthers 0.15–0.35;

styles 3-fid.

not persistent, dark yellow or medium or dark brown, ellipsoid, obovoid, or obpyriform, biconvex, angles obscure, 1.3–1.8 × 1–1.4 mm, apex rounded, neck absent or short, smooth at 30X, or sometimes finely rugulose at 10–20X with 20 or more horizontal ridges in vertical series.

whitish to olive or pale brown, sometimes spotted olive or red-brown, obovoid, trigonous (or subterete), angles prominent, 0.55–0.8 × 0.3–0.5 mm, apex constricted proximal to tubercle, smooth.

brown to whitish, pyramidal, much higher than wide to slightly depressed, sometimes spongy and with vertical rows of depressions, 0.4–0.8 × 0.3–0.8 mm.

green or pale brown to red-brown, trigonous.