Flora of North America species comparison

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

nodes terete, usually 1 exserted.

10-35 cm, erect or the bases decumbent;

nodes terete, 0-1 exserted.

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 1/4-3/4 their length, terete, apices acuminate;

innovation blades 0.5-1(2) mm wide, involute, moderately thick, moderately firm, abaxial surfaces smooth or scabrous, adaxial surfaces usually densely scabrous or hispidulous;

cauline blades usually gradually reduced distally, 0.5-1(2) mm wide, flat, folded, or involute, thin, sometimes withering, abaxial surfaces smooth or scabrous, apices narrowly prow-shaped, sometimes the flag leaf blades vestigial.

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.

2-8 cm, erect, narrowly lanceoloid to ovoid, contracted, congested;

nodes with 1-2 branches;

branches 0.5-3 cm, erect, terete to angled, 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.

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

florets 2-5;

rachilla internodes 0.5-1.2 mm, smooth or scabrous.

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.

lanceolate, distinctly keeled;

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

calluses glabrous;

lemmas 4-7 mm, lanceolate, distinctly keeled, membranous, keels and marginal veins usually softly puberulent, sometimes short-villous, intercostal regions usually glabrous, infrequently softly puberulent proximally, lateral veins moderately prominent, margins glabrous, apices acute;

palea keels scabrous;

anthers mostly vestigial (0.1-0.2 mm), rarely 2-3 mm.

= 28.

= unknown.