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.

8-35 cm tall, 0.5-0.9 mm thick, ascending to erect, slender;

nodes terete, 0(1) 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 1/5-1/3 their length, terete, smooth, glabrous, bases of basal sheaths glabrous;

collars smooth or scabrous, glabrous;

ligules 2-4 mm, smooth, apices acute, often lacerate;

innovation blades similar to the cauline blades;

cauline blades 1-2(3) mm wide, flat, thin, soft, smooth, narrowly prow-tipped, blades not strongly graduated or reduced upwards.

mostly intravaginal, some extravaginal.

mixed, mainly extravaginal or mainly pseudointravaginal, sometimes 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.

2-8 cm, slightly lax, usually loosely contracted and sparse, infrequently contracted and dense;

nodes with 1-3(5) branches;

branches 1-3(4) cm, usually ascending or weakly spreading, infrequently erect, fairly straight or flexuous, slender, sulcate or angled, smooth or the angles sparsely scabrous, with 1-8 spikelets.

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.

4-6 mm, lengths to 3 times widths, laterally compressed;

florets 2-5;

rachilla internodes shorter than 1 mm, smooth, 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.

nearly equaling or slightly longer than the adjacent lemmas, lanceolate to broadly lanceolate, thin, distinctly keeled, keels smooth or sparsely scabrous;

lower glumes 1-3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses glabrous or webbed, hairs usually shorter than 1/4 the lemma length, sparse;

lemmas 3-4.6 mm, lanceolate to broadly lanceolate, thin, distinctly keeled, keels and marginal veins short- to long-villous, lateral veins glabrous or sparsely softly puberulent, lateral veins obscure, intercostal regions glabrous, margins glabrous, apices acute;

paleas sparsely scabrous over the keels;

anthers (0.6)0.8-1.1(1.3) mm.

= 28.

= 28, 42, 84.