Flora of North America species comparison

15-60 cm, wiry, bases usually geniculate, strongly compressed;

nodes strongly compressed, some proximal nodes usually exserted.

20-55 cm, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 0-1 exserted.

closed for 1/10 – 1/5 their length, distinctly compressed, bases of basal sheaths glabrous;

ligules 1-3 mm, moderately to densely scabrous, ciliolate, apices obtuse;

blades 1.5-4 mm wide, flat, cauline blades subequal.

closed for 1/3-2/3 their length, terete, sparsely to moderately scabrous, glabrous or retrorsely hispidulous, bases of basal sheaths glabrous, distal sheath lengths 2.7-6.5(9.7) times blade lengths;

collars of at least some leaves usually sparsely hispidulous;

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

innovation blades to 40 cm, adaxial surfaces moderately to densely scabrous or hispidulous on and between the veins;

cauline blades steeply reduced in length distally, 1-3 mm wide, involute, moderately thick, soft, abaxial surfaces smooth, margins scabrous, apices narrowly prow-shaped, flag leaf blades 1-4.5 cm long.

extra- and intravaginal.

2-10 cm, generally 1/6 - 1/3 as wide as long, erect, linear, lanceoloid to ovoid, often interrupted, sparse to congested, with 15-80 spikelets and mostly with 1-3 branches per node;

branches 0.5-3 cm, erect to ascending, or infrequently spreading, angles densely scabrous, at least in part, with 1-15 spikelets.

4-8 cm, erect to nodding, lanceoloid to ovoid, loosely contracted, sparse, with 18-60 spikelets;

nodes with 1-2 branches;

branches 3-8 cm, ascending, lax, terete or weakly angled, moderately and sometimes coarsely scabrous, with 3-8 spikelets.

(2.3)3.5-7 mm, laterally compressed;

florets 3-7;

rachilla internodes usually shorter than 1 mm, smooth to muriculate.

6-9(11) mm, lengths to 3 times widths, laterally compressed, not sexually dimorphic;

florets 2-5(7);

rachilla internodes 1-2 mm, glabrous, scabrous, or sparsely to densely puberulent.

distinctly keeled;

lower glumes 3-veined;

calluses usually webbed, sometimes glabrous;

lemmas 2.3-3.5 mm, lanceolate, distinctly keeled, keels and marginal veins short-villous, intercostal regions glabrous, lateral veins obscure, margins glabrous, apices acute;

paleas scabrous over the keels;

anthers 1.3-1.8 mm.

subequal, distinctly keeled;

lower glumes 3-veined;

calluses diffusely webbed, hairs about 1/2 the lemma length;

lemmas 4-6(7) mm, lanceolate, distinctly keeled, glabrous, smooth or sparsely to moderately finely scabrous, keels scabrous, lateral veins moderately prominent, margins glabrous, apices acute;

palea keels scabrous, sometimes softly puberulent at midlength;

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

= 35, 42, 49, 50, 56, 84.

= 28.