Flora of North America species comparison

(7)15-60 cm tall, 1.5-2 mm thick, bases decumbent, terete or weakly compressed, smooth or moderately scabrous below the panicles;

nodes terete, 0(1) exserted.

(10) 25-80(120) cm tall, 0.4-1.75 mm thick, usually erect;

nodes terete, usually 1-2 exserted.

closed for about 1/2 their length, terete, glabrous or sparsely retrorsely scabrous, bases of basal sheaths glabrous, distal sheath lengths 1.7-4(6) times blade lengths;

collars smooth, glabrous;

ligules 1-5 mm, scabrous, truncate to acute, ciliolate;

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

cauline blades subequal in length, 2-4 mm wide, involute, thick, somewhat arcuate, firm, abaxial surfaces smooth or moderately to densely scabrous or hispidulous on and between the veins, apices narrowly prow-shaped, flag leaf blades 1-10 cm.

closed for 1/2 - 7/8 their length, usually weakly compressed and keeled, usually scabrous, rarely smooth;

ligules 1.5-5(10) mm, smooth or scabrous, acute;

blades 1-7(10) mm wide, flat, lax, soft, finely scabrous, apices narrowly prow-shaped, cauline blades 2-10 cm.

mostly intravaginal, some extravaginal.

intravaginal.

3-15 cm, erect, ovoid to lanceolate, contracted, often interrupted, congested, with 15-80 spikelets, rachises glabrous, smooth to moderately scabrous;

nodes with 1-2 branches;

branches 1-6 cm, erect, stiff, terete to weakly angled, smooth or sparsely to moderately scabrous, with 3-17 spikelets.

10-25(30) cm, erect, eventually open, with (1)3-5(7) branches per node;

branches eventually spreading or reflexed, fairly straight, angled, angles usually moderately to densely scabrous, rarely sparsely scabrous.

9-17 mm, lengths to 3 times widths, laterally compressed, not sexually dimorphic;

florets 3-6(10);

rachilla internodes smooth, usually hairy, hairs 0.3-0.4+ mm, rarely glabrous.

(2)4-6 mm, laterally compressed, with 2-5 florets;

rachilla internodes about 1 mm, smooth, usually softly puberulent, infrequently glabrous.

broadly lanceolate, subequal to the adjacent lemmas, distinctly keeled, keels sparsely scabrous near the apices;

lower glumes 3-veined;

upper glumes usually 7+ mm, 3-5-veined;

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

lemmas (6)7.5-11 mm, lanceolate, 5-7(11)-veined, distinctly keeled, keels and marginal veins, and sometimes the lateral veins, short-villous to softly puberulent, intercostal regions smooth or scabrous, glabrous or softly puberulent, margins glabrous, apices acute;

palea keels scabrous, intercostal regions glabrous;

anthers vestigial (0.1-0.2 mm) or (2)3-4(5) mm.

slightly unequal, lanceolate, distinctly keeled, keels and sometimes the lateral veins sparsely to moderately scabrous;

lower glumes 1-3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses of some or all florets sparsely webbed;

lemmas 2.5-3.5 mm, lanceolate to narrowly lanceolate, distinctly keeled, crisply puberulent proximally, hairs evenly distributed, finely scabrous distally, lateral veins obscure to prominent, margins narrowly hyaline, glabrous, apices narrowly acute, infrequently anthocyanic;

palea keels sparsely scabrous, glabrous or softly puberulent at midlength, intercostal regions usually softly puberulent;

anthers 3, 0.2-1 mm.

= 28.

= unknown.