Flora of North America species comparison

terete or cross section elliptic or rectangular, with 5–10 blunt ridges when dry, 25–50 cm × 0.5–1.2 mm, firm to hard, spongy.

not rooting at tips, terete, 10–40 cm, soft to firm, smooth.

distal leaf sheaths persistent, not splitting, mostly proximally dark red, distally red to brown or green, thinly papery, apex usually red-brown, often callose, subtruncate to obtuse, tooth usually present on some or all culms, to 0.9 mm.

distal leaf sheaths proximally brownish or sometimes reddish, distally stramineous to green.

usually ovoid or ellipsoid to subcylindric, rarely lanceoloid, 4–12 × (1.5–)2–3 mm, apex rounded to acute;

proximal scale amplexicaulous or clasping over 3/4 of culm, entire;

subproximal scale empty or with flower;

floral scales appressed in fruit, 30–100, 6–10 per mm of rachilla, orange-brown, midrib regions often greenish, oblong to ovate, 1.5–2.5 × 1–1.5 mm, apex entire, broadly rounded, sometimes acute in distal part of spikelet, usually horizontally wrinkled and recurved, often carinate in distal part of spikelet.

ovoid to oblong-subcylindric, 4–12 × 2–3.5 mm, apex acute to rounded;

proximal scale empty, clasping 1/2 of culm, like floral scales;

subproximal 1 or 2 scales often empty;

floral scales 20–100, 10 per mm of rachilla, entirely stramineous or sometimes red-brown, ovate, (1.5–)2–2.5 × 1.5 mm, apex broadly rounded, entire.

perianth bristles 5–6(–7), stramineous to medium brown, stout, often unequal, much shorter than to equaling achene, rarely all rudimentary;

stamens 3;

anthers dark yellow to stramineous, 0.8–1.5 mm;

styles 3-fid or some 2-fid.

perianth bristles (5–)6(–8), brown, stout, the longer equaling achene or tubercle, retrorsely spinulose;

stamens 3;

anthers brown, 1 mm.

falling with scales, dark brown, obovoid to obpyriform, compressed trigonous, angles evident to obscure, 0.7–1 × 0.65–0.8 mm, neck absent to sometimes long, finely rugulose at 10–30X, over 20 horizontal ridges in vertical series, and/or minutely cancellate at 20–30X.

falling with scales, obovoid, angles keeled, 0.8–1 × 0.7–0.8 mm, apex with short neck.

brown to whitish, pyramidal, as high as wide or sometimes greatly depressed, (0.1–)0.25–0.3 × 0.2–0.3 mm.

whitish to brown, mammillate to pyramidal, 0.2–0.3 × 0.3–0.35 mm, 1/3 or less as wide as achene.

= 20.