Flora of North America species comparison

often ascending or spreading, 4-angled or sometimes terete, sometimes sulcate, 1–7 cm × 0.2–0.3 mm, soft to firm.

markedly arched, not spirally twisted, not contracted near spikelet, when dry usually with several blunt to acute ridges and sulcate, subterete to slightly compressed, to 2 times as wide as thick, 5–15 cm × 0.5–1 mm, firm to hard;

culm tufts not proximally bulbous.

sheaths stramineous, distal sheaths often splitting abaxially, slightly inflated distally, oblique, apex acute.

distal leaf sheaths brown to reddish proximally, stramineous to reddish distally, apex sometimes reddish, membranous to papery.

ovoid, 1.5–4 × 0.8–2 mm, apex acute;

floral scales 4–15, 8 per mm of rachilla, colorless or reddish brown, midrib region green, ovate-lanceolate, not folded lengthwise, 1–1.5 × 0.5–0.7 mm, mibrib obscure to somewhat keeled, apex narrowly acute to acuminate, slightly recurved.

3–6 × 2–4 mm;

proximal scale empty, 2.5–4 mm, 1/2 or more as long as spikelet;

floral scales 4–9 per spikelet, 3.5–5 × 2 mm.

perianth bristles absent;

anthers 0.3–0.5 mm.

perianth bristles 4–7, very unequal, some shorter than 1/2 of achene, stout and smooth, others equaling or exceeding tubercle, very slender and densely spinulose;

anthers 1–1.5 mm.

with angles and longitudinal ridges ca. 6–10, rather prominent, broadly ovoid, less than 2 times longer then wide, (0.55–)0.65–0.75 × 0.3–0.4 mm, apex blunt, trabeculae distinct, 20–30.

medium brown, equilaterally trigonous to compressed trigonous or some biconvex, 1.5–2.1 × 0.9–1.2 mm, beak 0.2–0.3 × 0.3–0.4 mm.

grayish, mostly appressed, pyramidal, often depressed, 0.1–0.2 × 0.1–0.25 mm.

0.25–0.5 × 0.15–0.2 mm.