Flora of North America species comparison

15-70 cm, sometimes stout, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 0-1 exserted.

5-35 cm tall, 0.5-0.9 mm thick, erect or the bases decumbent, with 0(1) exserted nodes.

closed for about 1/3 their length, terete, smooth or scabrous, glabrous or occasionally retrorsely pubescent, bases of basal sheaths glabrous, distal sheath lengths usually (5)9+ times blade lengths;

collars smooth or scabrous, glabrous or hispidulous;

ligules 0.2-18 mm, smooth or scabrous, decurrent or not, apices truncate to acuminate, ciliolate or glabrous;

innovation blades usually moderately to densely scabrous or hispidulous on and between the veins, infrequently nearly smooth and glabrous;

cauline blades strongly reduced in length distally, (0.5)1-3(4) mm wide, usually involute, moderately thick and firm, infrequently moderately thin, abaxial surfaces usually smooth, infrequently scabrous, apices narrowly prow-shaped, steeply reduced in length distally along the culm, flag leaf blades often absent or very reduced, sometimes to 1(3) cm.

closed for 1/7 - 1/3 their length, terete, smooth or sparsely scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 2-4 times blade lengths;

collar margins smooth or scabrous to hispidulous;

ligules of cauline leaves 1-6 mm, colorless, translucent, smooth or scabrous, truncate to acute, ligules of the innovations 1-2.5 mm;

innovation blades similar to the cauline blades, 1.5-3 mm wide, involute, thick, frequently somewhat arcuate, abaxial surfaces smooth, adaxial surfaces densely scabrous or hispidulous;

cauline blades becoming only slightly shorter distally, 1.5-3 mm wide, involute, moderately thick, soft to moderately firm, abaxial surfaces smooth, apices narrowly prow-shaped.

mainly intravaginal, usually some extravaginal.

intravaginal.

2-12(30) cm, erect, contracted, narrowly lanceoloid to ovoid, congested, frequently with 100+ spikelets;

nodes with 1-2 branches;

branches 1-8 cm, erect, terete to weakly angled, smooth or scabrous, with 3-15(25) spikelets.

1-6 cm, erect, narrowly lanceoloid to ovoid, moderately congested, with 6-20(25) spikelets;

nodes with 1-2 branches;

branches 0.5-1.5(2) cm, erect, moderately stout, terete or weakly angled, angles smooth to fairly densely scabrous, with 1-3 spikelets.

(3)4-8(12) mm, lengths to 3 times widths, broadly lanceolate to ovate, laterally compressed, not sexually dimorphic;

florets 2-7(13);

rachilla internodes 0.8-1.3 mm, smooth, glabrous or hairy, hairs to 0.3 mm.

6-8(12) mm, lengths to 3.5 times widths, broadly lanceolate, laterally compressed, not sexually dimorphic, lustrous;

florets 2-5;

rachilla internodes smooth.

lanceolate, distinctly keeled;

lower glumes 1-3-veined, distinctly shorter than the lowest lemmas;

calluses glabrous;

lemmas 3-6 mm, lanceolate, distinctly keeled, keels, marginal veins, and lateral veins glabrous or short- to long-villous or softly puberulent, lateral veins moderately prominent, intercostal regions softly puberulent or glabrous, smooth or sparsely scabrous, margins glabrous, apices acute;

palea keels scabrous, sometimes softly puberulent or long-villous at midlength, hairs to 0.4+ mm;

anthers vestigial (0.1-0.2 mm) or 2-3 mm.

subequal, isomorphic, lanceolate to broadly lanceolate, thin, lustrous, distinctly keeled, keels smooth or sparsely scabrous;

lower glumes shorter than the adjacent lemmas, 3-veined;

calluses glabrous;

lemmas 5-8 mm, lanceolate, distinctly keeled, thinly membranous, smooth or sparsely finely scabrous, glabrous, lateral veins moderately prominent, margins glabrous, apices acute;

palea keels coarsely scabrous;

anthers vestigial (0.1-0.2 mm) or 2-4 mm.

= 28+11, 56, 56-58, 58-64.

= unknown.