Flora of North America species comparison

fibrous, principally adventitious.

10–15 mm diam.

bluntly trigonous with nearly flat sides throughout to cylindric proximally, obscurely trigonous distally, 1–4 m × 4–10 mm, smooth.

(culms) usually trigonous, occasionally terete, rarely compressed, usually solid, rarely hollow or septate.

3–4, basal, ca. 1/6 culm length;

sheath fronts coarsely pinnate-fibrillose;

blades 0–1, dorsiventrally flat, not more than 1/2 sheath length, distal blade to 20 × 2 mm.

basal and/or cauline, alternate, usually 3-ranked, rarely 2-ranked or multi-ranked, bases forming cylindric sheaths enclosing stem, margins usually fused;

junction of sheaths and blades often with adaxial flaps of tissue or fringes of hair (ligules);

blades frequently absent from some basal leaves, rarely from cauline leaves, when present divergent or ascending, flat, folded, plicate, rolled, or terete, linear, venation parallel.

3 or more times branched, branches to 21 cm;

proximal bract usually erect, obtusely trigonous to subcylindric-channeled, 1–8 cm, margins often scabridulous.

25–150+, solitary and in clusters of 2 or more, 5–11 × 3 mm;

scales orange-brown, brightly lineolate-spotted, broadly oval, 2.5 × 2 mm, margins ciliolate, flanks veinless, apex rounded, notch 0.1–0.2 mm deep, awn not contorted, usually bent outward, 0.3 mm, sparsely scabrous.

perianth members 2–4, dark red-brown, thickly strap-shaped or trigonous, equaling achenes, fringed with brownish, soft, blunt hairs;

anthers 1.5 mm;

styles 2-fid.

hypogynous, bisexual in most genera, unisexual in Scleria, Carex, Cymophyllus, and Kobresia;

perianth absent or with (1–)3–6(–30) bristles and/or scales, usually falling off with fruit;

stamens usually (1–)3, rarely more, usually distinct;

anthers basifixed;

pistils 1, 2–3(–4)-carpellate, fused, locule 1;

style undivided or branches 2–3(–4);

stigma sometimes papillate.

achenes, usually trigonous or biconvex;

pericarps thin (except in Scleria).

dark gray-brown when ripe, unequally biconvex or plano-convex, ovoid to obovoid, 1.8–2.2 × 1.3 mm;

beak 0.2 mm.

1;

testa thin, free from pericarp;

embryo basal;

endosperm abundant.

inflorescences (spikelets) a shortened axis; glumaceous bracts (scales) 1–many, spirally arranged, sometimes 2-ranked, usually appressed or ascending;

scales usually all fertile, each subtending a single flower, sometimes proximal and/or distal scales empty;

lateral spikes often with basal, usually empty, usually 2-keeled scale (prophyll); occasionally prophyll subtending and enclosing rachilla, bearing 1 pistillate, sometimes (0–)3 staminate flowers and empty scales (Carex, Cymophyllus, and Kobresia).

inflorescences panicles, often modified to corymb, pseudoumbel, cyme (anthela), raceme, spike, or capitulum (head), rarely single spike, usually subtended by foliaceous or, less frequently, glumaceous bracts;

secondary inflorescences sometimes simulating spikelets (Carex, Cymophyllus, and Kobresia).

= 5–ca. 100.

= 68.