Flora of North America species comparison

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

acutely quadrangular, (30–)45–105 cm × (1–)2–5.4 mm, soft to firm, internally spongy, transverse septa incomplete;

plants never forming filiform, flaccid culms.

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

distal leaf sheaths persistent, membranous, apex narrowly acute to acuminate, sometimes prolonged into a bladelike portion to 8 cm.

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.

not proliferous, (15–)20–76 × 3–5(–6) mm;

rachilla joints bearing obscure winglike remnants of floral scales;

proximal scale empty, amplexicaulous, (1–)2.2–5.4 mm;

floral scales (28–)45–135, 2–3 per mm of rachilla, stramineous to pale brown, usually with pale to dark brown submarginal band, midrib region sometimes greenish, broadly obovate to ovate, (4–)4.5–6.2 × 2.8–5 mm, subcartilaginous, apex rounded to obtuse.

perianth bristles present or sometimes apparently absent;

stamens 3;

anthers 0.15–0.35;

styles 3-fid.

perianth bristles 6–7, whitish to brown, slender, often markedly unequal, shorter than achene or some equalling tubercle, sparsely retrorsely spinulose to smooth;

anthers stramineous to red-brown, 2.3–2.9 mm;

styles 3-fid, sometimes 2-fid.

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.

yellow or pale green to brown or purplish, biconvex, obovoid to obpyriform, 1.8–3 × 1.3–2 mm, almost smooth to markedly sculptured at 10–15X, each face with 19–38 rows of almost linear, transversely elongated cells, which are sometimes isodiametric at achene base, apex often constricted to neck 0.3–0.4 mm wide.

green or pale brown to red-brown, trigonous.

dark brown or whitish, deltoid to high-pyramidal or lanceoloid, 0.7–1.5 × 0.4–1 mm, often spongy.