Flora of North America species comparison

diffuse, very fine.

stiff or flaccid, usually terete, ribbed.

(10–)15–40(–50) cm.

basal, polystichous, spreading to ascending;

sheaths open apically, apex fimbriate-ciliate, rarely entire;

ligules absent, lateral tufts of hair at junction of blade and sheath;

blades mostly linear or filiform, coarsely ribbed, usually longer than sheaths, 1 mm wide or less, mostly strongly involute, margins variably scabrid-ciliate.

1/2 length of culms;

sheaths brown to red-brown, glabrous, or scabrid along ribs;

blades narrowly linear, 0.7–1 mm wide, flat or involute, glabrous or scabrid along ribs, margins distally scabrid.

terminal on slender scapes, rarely axillary to culm leaves, simple or compound anthelae or spikelet solitary;

spikelets 1–50+;

involucral bracts (1–)2–8, spreading or erect, leaflike or scalelike.

scapes 5, erect to ascending, terete, many ribbed, 1–2 mm thick, stiff;

spikelets in dense globose to hemispheric, involucrate heads, 1–2 cm wide;

longer involucral bracts with setaceous blades usually exceeding inflorescence, basally dilating to broad pectinatefimbriate sheaths.

mostly ovoid to lanceoloid or lance-cylindric;

scales 6–50, spirally arranged, rarely nearly distichous, each subtending flower or 1–2 proximal scales empty.

pale brown or redbrown, ovoid, somewhat flattened, 4–5 mm;

fertile scales ovate, keeled, 4–5 mm, apex acute, puberulent, midrib included or excurrent as mucro.

bisexual;

perianth absent;

stamens 1–3;

styles slender, (2–)3-fid, glabrous, base enlarged, persistent in fruit.

stamens 3;

anthers linear, 3 mm.

trigonous or 3-lobed, rarely biconvex, usually 3-ribbed.

white or yellowish, broadly trigonous-obovoid, 3-lobed, 1 mm, each lobe carinate, biconvex, apex retuse, surface coarsely, transversely rugose;

tubercle a minute, dark button.

= 30.