Flora of North America species comparison

25-90 cm.

spindly to stout, terete or weakly to strongly compressed;

nodes 0-5, exserted.

closed for 1/2 - 3/4 their length, smooth or sparsely scabrous, margins not ciliate;

ligules 0.3-2.1 mm, smooth or sparsely scabrous, truncate to obtuse, ciliolate;

blades 0.6-3.5 mm wide, flat.

terete or weakly to strongly compressed, closed only at the base or up to full length, fusion of the margins not extended by a hyaline membrane, basal sheaths usually glabrous, rarely sparsely retrorsely strigose, hairs about 0.1 mm;

ligules 0.1-18 mm, thinly membranous and white to milky white or hyaline, truncate to acuminate, entire or erose to lacerate, smooth or ciliolate;

blades flat, folded, or involute, thin to thick, smooth or sparsely to densely scabrous, adaxial surfaces glabrous or hairy, hispidulous or puberulent, apices narrowly to broadly prow-shaped.

mainly pseudointravaginal.

intra- and/or extravaginal or pseudointravaginal.

7.5-15(18) cm, lax, pyramidal, open, sparse;

nodes with 1-3(5) branches;

branches 3-8 cm, ascending, straight to spreading, angled, angles prominent, scabrous.

1-41 cm, erect to nodding or lax, tightly contracted to open, with 1-100+ spikelets;

branches 0.5-20 cm, erect to reflexed, terete or angled, smooth or sparsely to densely scabrous, usually glabrous, rarely hispidulous, with 1 to many spikelets.

4-6.5 mm, laterally compressed;

florets 2-5;

rachilla internodes to 1 mm, smooth, glabrous.

2-12 mm, subterete to strongly laterally compressed, sometimes bulbiferous;

florets (1)2-8(13);

rachilla internodes smooth or scabrous, glabrous or pubescent.

1/2-1/3 the length of the adjacent lemmas, distinctly keeled, keels scabrous;

lower glumes subulate to narrowly lanceolate, (1)3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas (2.5)3.2-4.7 mm, lanceolate, green, distinctly keeled, keels and marginal veins long-villous, hairs extending up almost the whole keel length, lateral veins prominent, intercostal regions smooth, minutely bumpy, usually glabrous, rarely sparsely softly puberulent, apices acute, blunt, or pointed, white, not bronze;

palea keels softly puberulent at midlength, apices scabrous;

anthers (0.5)0.8-1.2(1.5) mm.

shorter than to slightly exceeding the adjacent lemmas, weakly to distinctly keeled, smooth or scabrous;

calluses blunt, usually terete or slightly laterally compressed, sometimes slightly dorsally compressed, glabrous, dorsally webbed, diffusely webbed, or with a crown of hairs;

lemmas 1.7-11 mm, rounded to weakly or distinctly keeled, thinly membranous to chartaceous, glabrous or hairy on the keel and veins, sometimes the intercostal regions also hairy, 5-7(11)-veined, margins smooth or scabrous, glabrous, apices obtuse to acuminate;

palea keels usually scabrous, infrequently smooth, glabrous or with hairs;

anthers (1-2)3, 0.1-4.5(5) mm.

= 28.