Flora of North America species comparison

(5)10-30 cm tall, 1.2-1.5 mm thick, bases decumbent, terete or weakly compressed, hispidulous beneath the panicles;

nodes terete, 0(1) exserted.

10-55 cm, erect or the bases decumbent, terete or weakly compressed;

nodes terete, not exserted.

closed for about 1/2 their length, terete, smooth or sparsely to moderately retrorsely scabrous near the collars, glabrous, bases of basal sheaths glabrous, distal sheath lengths 0.9-3.5 times blade lengths;

collars sparsely to moderately retrorsely scabrous, glabrous;

ligules 1-2 mm, scabrous, truncate to obtuse, ciliolate;

innovation blades to 30 cm long, adaxial surfaces moderately to densely scabrous or hispidulous on and between the veins;

cauline blades subequal in length, 1-2 mm wide, involute, moderately thick, moderately firm, arcuate, abaxial surfaces smooth or sparsely scabrous, adaxial surfaces moderately to densely scabrous or hispidulous on and between the veins, apices narrowly prow-shaped, flag leaf blades 1-9 cm.

closed for about 1/3 their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths 1.5-7.5 times blade lengths;

collars smooth, glabrous;

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

innovation blades similar to the cauline blades, adaxial surfaces nearly smooth, glabrous on and between the veins;

cauline blades fairly strongly reduced in length distally, 1-3 mm wide, folded to involute, moderately thick, moderately firm, abaxial surfaces smooth, apices narrowly prow-shaped, flag leaf blades 1-5.5 cm.

mainly intravaginal, some extravaginal.

extra- and intravaginal.

1.5-6 cm, erect, compact, ovoid, contracted, infrequently interrupted, congested, with 15-50 spikelets;

nodes with 1-2 branches, internodes densely hispidulous;

branches 0.5-2 cm, erect, stiff, terete to weakly angled, densely hispidulous, with 1-5 spikelets.

3-7 cm, erect, lanceoloid to ovoid, congested, with 20-70 spikelets;

nodes with 1-2 branches;

branches 0.5-3 cm, erect, terete, usually smooth, infrequently sparsely scabrous distally, with 3-12 spikelets.

7-12 mm, lengths to 3 times widths, laterally compressed, not sexually dimorphic;

florets 3-6;

rachilla internodes usually shorter than 0.5 mm, smooth, glabrous.

3.5-5.5 mm, lengths to 3 times widths, laterally compressed, very compact, not sexually dimorphic;

florets 2-5;

rachilla internodes about 0.5 mm, smooth, glabrous.

broadly lanceolate, 1/2 as long as to subequal to the adjacent lemmas, distinctly keeled;

lower glumes 3-veined;

upper glumes 4-4.5(7+) mm, 3-veined;

calluses usually with a crown of hairs, sometimes glabrous or diffusely webbed;

lemmas 5-7.5 mm, lanceolate, 5-veined, distinctly keeled, keels, marginal veins, and sometimes the lateral veins short- to long-villous or softly puberulent, rarely glabrous, lateral veins moderately prominent, intercostal regions smooth, glabrous, margins glabrous, apices acute;

palea keels scabrous to pectinate-ciliate, intercostal regions glabrous;

anthers vestigial (0.1-0.2 mm) or (2)2.5-3.5 (4) mm.

broadly lanceolate, distinctly shorter than the adjacent lemmas, distinctly keeled, keels smooth or sparsely scabrous;

lower glumes 3-veined;

calluses glabrous;

lemmas 2.5-3.5 mm, lanceolate, usually purplish, distinctly keeled, glabrous, smooth, margins glabrous, apices acute;

palea keels scabrous, intercostal regions glabrous;

anthers vestigial (0.1-0.2 mm) or 1.5-2 mm.

= 28.

= 28.