Flora of North America species comparison

20-100 cm tall, about 2 mm thick, terete or weakly compressed;

nodes terete, 0-1 exserted.

31-126 cm.

closed for 1/6-1/3 their length, sometimes fused by a hyaline membrane to 3/4 their length, terete, bases of some basal sheaths densely retrorsely hairy, hairs 0.1-0.2 mm, thick;

ligules 1-3.5 mm, yellow-cream to brown, truncate, erose, ciliolate;

blades (2)4-11 mm wide, flat, thick, smooth or sparsely scabrous, apices broadly prow-shaped.

closed for 1/2 - 7/8 their length;

ligules 0.1-1.7(2.1) mm, smooth or sparsely scabrous, truncate to obtuse;

blades 0.8-4.1 mm wide, flat, lax.

extravaginal.

mainly pseudointravaginal.

8-30 cm, erect, loosely contracted, fairly congested, with 40-100+ spikelets;

branches 3-10 cm, steeply ascending, terete, smooth or sparsely scabrous, sometimes with tufts of hair at the nodes, with 5-20 spikelets.

11.4-36 cm, erect or lax, narrowly pyramidal, usually open, infrequently contracted;

nodes with (2)3-5(7) branches;

branches spreading, straight, angled, angles sparsely to moderately scabrous.

5-12 mm, laterally compressed;

florets 2-6;

rachilla internodes smooth, infrequently sparsely puberulent.

3.5-6.7 mm, laterally compressed;

florets 2-4;

rachilla internodes glabrous.

lanceolate, subequal or the upper glumes to 2 mm longer than the lower glumes, sometimes exceeding the lowest lemmas, distinctly keeled, smooth, often glaucous, acute to acuminate;

lower glumes 4-9.5 mm, 1-3(5)-veined;

upper glumes 5.5-10 mm, (1)3(5)-veined;

calluses of proximal lemmas usually with a crown of hairs, hairs 1-2 mm;

lemmas 4.5-7 mm, lanceolate, 5-7-veined, distinctly keeled, thinly membranous, glabrous or the keels and marginal veins long-villous, intercostal regions glabrous or hispidulous, moderately to densely scabrous, margins usually with hairs to 0.2 mm proximally, apices acute;

palea keels scabrous;

anthers 1.7-3.2 mm.

ovate, distinctly keeled, keels scabrous;

lower glumes 1-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas 2.7-4.2(5) mm, lanceolate, distinctly keeled, keels short-villous to about midlength, marginal and lateral veins glabrous, lateral veins obscure or moderately prominent, intercostal regions glabrous, smooth, apices acute;

paleas glabrous or ciliolate over the keels, apices finely scabrous;

anthers 0.4-0.8 mm.

= 28, 29+-, 42, 62.

= unknown.