Flora of North America species comparison

2-20(45) cm, prostrate to erect, slender;

nodes terete, usually 1 exserted.

30-90 cm, slender to coarse.

closed for about 1/3 their length, terete or weakly compressed, smooth;

ligules 0.5-3(5) mm, smooth, glabrous, decurrent, obtuse to truncate;

blades 1-10 cm long, 1-3(6) mm wide, flat or weakly folded, thin, soft, smooth, margins usually slightly scabrous, apices broadly prow-shaped.

closed for 1/20 – 1/10 their length, terete, scabrous, glabrous;

collars smooth to scabrous;

ligules 0.5-4(6) mm, scabrous, apices truncate to acute, entire or lacerate;

innovation blades 15-30 cm;

cauline blades 1-4 mm wide, involute or rarely flat, moderately thick and firm, both surfaces sparsely to densely antrorsely scabrous, apices narrowly prow-shaped, flag leaf blades usually longer than their sheaths.

intravaginal, innovations common, similar to the culms.

intra-vaginal.

1-7(10) cm, lengths 1.2-1.6 times widths, erect;

nodes with 1-2(3) branches;

branches ascending to spreading or reflexed, straight, terete, smooth, with crowded or loosely arranged spikelets.

(7)10-30 cm, erect, pyramidal, open, with 2-5 branches per node;

branches 2-8(15) cm, spreading, straight, angled, angles moderately to densely scabrous, sometimes densely scabrous all over, with 10-30 spikelets.

3-5 mm, laterally compressed;

florets 2-6;

rachilla internodes smooth, glabrous, concealed or exposed, distal internodes less than 1/2(3/4) the length of the distal lemma.

4-7 mm, lanceolate, laterally compressed;

florets 2-5;

rachilla internodes 0.8-1.5 mm, smooth or scabrous, sometimes sparsely hispidulous.

smooth, distinctly keeled, keels smooth;

lower glumes 1-veined;

upper glumes shorter than or subequal to the lowest lemma;

calluses glabrous;

lemmas 2.5-4 mm, lanceolate, distinctly keeled, smooth throughout, the keels, marginal veins, and, usually, lateral veins crisply puberulent to long-villous, rarely glabrous throughout, lateral veins prominent, intercostal regions glabrous, margins smooth, glabrous, apices obtuse to acute;

palea keels smooth, usually short- to long-villous, rarely glabrous;

anthers 0.6-1.1 mm, oblong prior to dehiscence, those of the upper 1-2 florets usually vestigial.

sparsely to rarely densely scabrous;

lower glumes 1-3-veined;

calluses usually glabrous, rarely sparsely short-webbed;

lemmas 2.5-3.5 mm, lanceolate, distinctly keeled, smooth or sparsely to densely scabrous, keels and marginal veins glabrous or softly puberulent or short- to long-villous, lateral veins moderately prominent to prominent, intercostal regions usually glabrous, infrequently sparsely softly puberulent, apices acute;

palea keels scabrous;

anthers aborted late in development, or 2.2-2.5 mm.

= 28.

= 28+1, 28-29+11.