Flora of North America species comparison

15-80 cm, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 0-1 exserted.

8-12(20) cm, slender, bases decumbent, terete or weakly compressed;

nodes terete, 1 exserted.

closed for 1/10 – 1/5(1/4) their length, terete, smooth or sparsely scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths (1.2)1.5-9(20) times blade lengths;

ligules (1)1.5-4(5) mm, smooth or sparsely to moderately scabrous, apices obtuse to acute;

blades strongly to gradually reduced in length distally, 1.5-5 mm wide, flat and moderately thin to folded and moderately thick and firm, abaxial surfaces smooth, adaxial surfaces smooth or sparsely to moderately scabrous, primarily over the veins, apices narrowly prow-shaped, flag leaf blades (0.4)1-7(10) cm.

closed for 1/4-1/3 their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths 2-4 times blade lengths;

collars smooth, glabrous;

ligules 0.6-1 mm, smooth, glabrous, truncate;

blades 2-3 mm wide, flat, thin, soft, smooth, apices broadly prow-shaped, cauline blades subequal.

intra- and extravaginal.

intravaginal.

(2.5)4-12(18) cm, erect, usually narrowly lanceoloid, contracted, sometimes interrupted, infrequently loosely contracted, usually congested, with 25-100 spikelets;

nodes with 1-5 branches;

branches 1-9 cm, erect to infrequently ascending, rarely spreading, terete to weakly angled, smooth or the angles sparsely to moderately scabrous, with 3-24 spikelets.

2.5-5 cm, lengths 1-2 times widths, erect, loosely contracted or open, ovoid to pyramidal, sparse, with 10-25(30) spikelets and 1-2 branches per node;

branches 1-3 cm, spreading to reflexed, straight, terete, smooth or sparsely scabrous, with 2-5(8) spikelets.

3.2-7 mm, lengths to 3.5(3.8) times widths, laterally compressed;

florets 2-7;

rachilla internodes smooth, sometimes sparsely puberulent.

4-6 mm, laterally compressed;

florets 3-7;

rachilla internodes smooth, glabrous, more or less concealed, distal internode less than 1/2 the length of the distal lemma.

lanceolate, distinctly keeled, smooth or sparsely scabrous;

lower glumes 3-veined;

calluses usually glabrous, infrequently webbed, hairs to 1/4 the lemma length;

lemmas 2.5-4.5 mm, lanceolate to narrowly lanceolate, distinctly to weakly keeled, keels and marginal veins short- to long-villous, lateral veins moderately prominent, glabrous or puberulent, intercostal regions usually glabrous, infrequently hairy, hairs to 0.3 mm, margins glabrous, apices acute or blunt;

palea keels scabrous, glabrous or short-villous at midlength, intercostal regions usually glabrous, sometimes puberulent to short-villous;

anthers 1.3-2.2 mm.

distinctly keeled, keels smooth;

lower glumes 1-veined;

calluses glabrous;

lemmas 1.7-4 mm, lanceolate, distinctly keeled, smooth throughout, proximal lemmas glabrous throughout or the keels and marginal veins sparsely short-villous, distal lemmas glabrous or the keels and marginal veins short-villous to near the apices, lateral veins moderately prominent, intercostal regions glabrous, margins smooth, glabrous, apices obtuse to acute;

palea keels smooth, sometimes sparsely softly puberulent to short-villous;

anthers (1.25)1.5-2.5 mm, cylindrical prior to dehiscence, those of the upper 1-2 florets commonly vestigial.

= 56, 56+1, 56-58, 63, 64, 70, 76, 84, ca. 90, 95+-5, 100, 103.

= 14.