Flora of North America species comparison

15-60 cm, wiry, bases usually geniculate, strongly compressed;

nodes strongly compressed, some proximal nodes usually exserted.

7-25 cm.

closed for 1/10 – 1/5 their length, distinctly compressed, bases of basal sheaths glabrous;

ligules 1-3 mm, moderately to densely scabrous, ciliolate, apices obtuse;

blades 1.5-4 mm wide, flat, cauline blades subequal.

closed for 1/7-1/4(1/3) their length, terete;

ligules of cauline leaves 1-3 mm, milky white, usually densely scabrous, sometimes smooth, ligules of the upper innovation leaves 0.5-2.5 mm;

innovation blades adaxially scabrous, hispidulous, or puberulent on and between the veins, lacking papillae on the long cells (at 100x);

cauline blades folded to involute, moderately thick, soft or moderately firm, apices narrowly prow-shaped, flag leaf blades 1-2 mm wide, adaxial surfaces with 5-9 well-spaced ribs.

all or mainly intravaginal.

2-10 cm, generally 1/6 - 1/3 as wide as long, erect, linear, lanceoloid to ovoid, often interrupted, sparse to congested, with 15-80 spikelets and mostly with 1-3 branches per node;

branches 0.5-3 cm, erect to ascending, or infrequently spreading, angles densely scabrous, at least in part, with 1-15 spikelets.

3-6 cm, erect, narrowly lanceoloid, contracted, moderately congested;

nodes with 1-2 branches;

branches to 1.5 cm, erect, slender, terete, sulcate or angled, smooth or the angles moderately scabrous;

pedicels shorter than the spikelets.

(2.3)3.5-7 mm, laterally compressed;

florets 3-7;

rachilla internodes usually shorter than 1 mm, smooth to muriculate.

4.2-7 mm, laterally compressed, often strongly anthocyanic;

florets 2-4;

rachilla internodes 1-1.5 mm, smooth, sometimes sparsely hispidulous.

distinctly keeled;

lower glumes 3-veined;

calluses usually webbed, sometimes glabrous;

lemmas 2.3-3.5 mm, lanceolate, distinctly keeled, keels and marginal veins short-villous, intercostal regions glabrous, lateral veins obscure, margins glabrous, apices acute;

paleas scabrous over the keels;

anthers 1.3-1.8 mm.

lanceolate, distinctly keeled, keels smooth;

lower glumes shorter than to equaling the lowest lemmas, 3-veined;

upper glumes frequently exceeding the lowest lemmas, 3-5-veined, exceeded by the upper lemmas;

calluses glabrous;

lemmas 4.1-5.8 mm, narrowly lanceolate, distinctly keeled, thin, glabrous, apices acute;

palea keels scabrous;

anthers 0.8-1.2(1.7) mm, infrequently aborted late in development.

= 35, 42, 49, 50, 56, 84.

= unknown.