Flora of North America species comparison

25-120 cm, erect or the bases decumbent, sometimes branching above the base, terete or weakly compressed, scabrous below the panicle;

nodes terete or slightly compressed, proximal nodes often slightly swollen, uppermost node at or above (73)72 the culm length.

7-30 (35) cm tall, 0.4-0.9 mm thick, slender, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 0-1 exserted.

closed for 1/10 – 1/5 their length, slightly compressed, glabrous or sparsely retrorsely scabrous, bases of basal sheaths glabrous, distal sheath lengths 0.7-2.2 times blade lengths;

ligules (1)1.5-6 mm, smooth or sparsely to moderately scabrous, apices obtuse to acute, frequently lacerate, usually minutely ciliolate;

blades 1.5-8 mm wide, flat, usually several per culm, steeply ascending or spreading to 80°, often lax distally, apices narrowly prow-shaped.

closed for 1/3-2/3 their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths (1)1.4-4.5 times blade lengths;

collars smooth, glabrous;

ligules 0.5-1.5(2.2) mm, scabrous, truncate to acute;

innovation blades adaxially moderately to densely scabrous or hispidulous on and between the veins;

cauline blades slightly reduced in length distally, 0.5-1(1.5) mm wide, involute, thin to moderately thick, usually filiform, soft, abaxial surfaces smooth, adaxial surfaces sparsely scabrous on and between the veins, apices narrowly prow-shaped, flag leaf blades (0.5)1-5 cm.

extravaginal or mixed extra- and intravaginal.

mainly intravaginal, some extravaginal.

(9)13-30(41) cm, lengths 73-72 times widths at maturity, lax, eventually open, sparsely to moderately congested, with 25-100+ spikelets;

nodes with 2-9 branches;

branches 4-15 cm, 3/10 – 1/2 the panicle length, initially erect, eventually widely spreading to slightly reflexed, fairly straight, slender, angles densely scabrous.

1-5(7) cm, erect, ovoid, fairly tightly to loosely contracted, congested or moderately congested, with fewer than 50 spikelets;

nodes with 1-2 branches;

branches 0.5-3 cm, erect to ascending, slightly lax, terete or angled, angles sparsely to densely scabrous, with 2-12 spikelets.

3-5 mm, lengths 3-3.5 times widths, narrowly to broadly lanceolate, laterally compressed;

florets (1)2-5;

rachilla internodes mostly shorter than 1 mm, usually muriculate, sometimes smooth, rarely sparsely hispidulous.

3-6(8) mm, lengths to 3 times widths, laterally compressed, compact, not sexually dimorphic;

florets 2-5;

rachilla internodes 0.8-1.1 mm, usually not readily visible from the sides, glabrous or sparsely puberulent.

subulate to lanceolate, distinctly keeled, keels smooth or sparsely scabrous;

lower glumes with lengths 6.4-10 times widths, 3-veined, long-tapered to a slender point;

calluses sparsely to moderately densely webbed, hairs (1/2)2/3 the lemma length;

lemmas 2-3 mm, narrowly lanceolate to lanceolate, distinctly keeled, keels straight or gradually arched, usually abruptly inwardly arched at the junction of the scarious apices, keels and marginal veins short-villous, lateral veins obscure, intercostal regions muriculate, glabrous, margins distinctly inrolled, glabrous, apices obtuse or acute, usually partially bronze-colored, frequently incurved and blunt with a short, hyaline margin;

palea keels scabrous, intercostal regions glabrous;

anthers 1.3-1.8 mm.

slightly unequal, distinctly keeled, keels smooth or scabrous;

lower glumes 2-4 mm, 1-3-veined, about 2/3 the length of the adjacent lemmas;

upper glumes 2.9-5 mm;

calluses usually diffusely webbed, hairs 1-2 mm, infrequently glabrous;

lemmas 2.5-4(4.5) mm, lanceolate, distinctly keeled, moderately to densely finely scabrous, glabrous throughout or the keels and sometimes the marginal veins sparsely puberulent proximally, margins narrowly scarious, glabrous, apices acute;

paleas subequal to the lemmas, keels scabrous, intercostal regions glabrous;

anthers vestigial (0.1-0.2 mm) or 1.5-2 mm.

= 28, 30, 32, 35, 42, 56, 84.

= 42.