Flora of North America species comparison

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

nodes terete, usually 1 exserted.

50-120 cm, stout.

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 1/2 - 3/4 their length, distinctly compressed, keels winged, bases of basal sheaths glabrous;

ligules 1-2 mm, smooth or sparsely scabrous, apices truncate;

blades (4)6-15 mm wide, flat or folded, apices broadly and abruptly prow-shaped.

intravaginal, innovations common, similar to the culms.

extravaginal.

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.

10-20 cm, ovoid to pyramidal, open, spikelets numerous, with 3-5 branches per node;

branches ascending to spreading, angled, angles densely scabrous.

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.

4-9 mm, laterally compressed;

florets 3-5;

rachilla internodes about 1 mm, scabrous, glabrous.

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.

distinctly keeled, keels scabrous;

lower glumes 1-3-veined;

calluses glabrous;

lemmas 3.5-4.5 mm, narrowly lanceolate, distinctly keeled, scabrous, glabrous throughout, lateral veins prominent, apices acute;

palea keels scabrous, glabrous;

anthers 1.5-3 mm.

= 28.

= 14.