Flora of North America species comparison

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

nodes terete, 0-1 exserted.

10-35 cm, erect or the bases decumbent;

nodes terete, 0-1 exserted.

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 1/4-3/4 their length, terete, apices acuminate;

innovation blades 0.5-1(2) mm wide, involute, moderately thick, moderately firm, abaxial surfaces smooth or scabrous, adaxial surfaces usually densely scabrous or hispidulous;

cauline blades usually gradually reduced distally, 0.5-1(2) mm wide, flat, folded, or involute, thin, sometimes withering, abaxial surfaces smooth or scabrous, apices narrowly prow-shaped, sometimes the flag leaf blades vestigial.

extravaginal.

intra-vaginal.

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.

2-8 cm, erect, narrowly lanceoloid to ovoid, contracted, congested;

nodes with 1-2 branches;

branches 0.5-3 cm, erect, terete to angled, scabrous.

5-12 mm, laterally compressed;

florets 2-6;

rachilla internodes smooth, infrequently sparsely puberulent.

4-8 mm, lengths to 3 times widths, broadly lanceolate to narrowly ovate, laterally compressed, not sexually dimorphic;

florets 2-5;

rachilla internodes 0.5-1.2 mm, smooth or scabrous.

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.

lanceolate, distinctly keeled;

lower glumes 3-veined, distinctly shorter than the lowest lemmas;

calluses glabrous;

lemmas 4-7 mm, lanceolate, distinctly keeled, membranous, keels and marginal veins usually softly puberulent, sometimes short-villous, intercostal regions usually glabrous, infrequently softly puberulent proximally, lateral veins moderately prominent, margins glabrous, apices acute;

palea keels scabrous;

anthers mostly vestigial (0.1-0.2 mm), rarely 2-3 mm.

= 28, 29+-, 42, 62.

= unknown.