Flora of North America species comparison

2-20(45) cm, prostrate to erect, slender;

nodes terete, usually 1 exserted.

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

nodes terete, 0-1 exserted.

closed for about 1/3 their length, terete or weakly compressed, smooth;

ligules 0.5-3(5) mm, smooth, glabrous, decurrent, obtuse to truncate;

blades 1-10 cm long, 1-3(6) mm wide, flat or weakly folded, thin, soft, smooth, margins usually slightly scabrous, apices broadly prow-shaped.

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.

intravaginal, innovations common, similar to the culms.

extravaginal.

1-7(10) cm, lengths 1.2-1.6 times widths, erect;

nodes with 1-2(3) branches;

branches ascending to spreading or reflexed, straight, terete, smooth, with crowded or loosely arranged spikelets.

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.

3-5 mm, laterally compressed;

florets 2-6;

rachilla internodes smooth, glabrous, concealed or exposed, distal internodes less than 1/2(3/4) the length of the distal lemma.

5-12 mm, laterally compressed;

florets 2-6;

rachilla internodes smooth, infrequently sparsely puberulent.

smooth, distinctly keeled, keels smooth;

lower glumes 1-veined;

upper glumes shorter than or subequal to the lowest lemma;

calluses glabrous;

lemmas 2.5-4 mm, lanceolate, distinctly keeled, smooth throughout, the keels, marginal veins, and, usually, lateral veins crisply puberulent to long-villous, rarely glabrous throughout, lateral veins prominent, intercostal regions glabrous, margins smooth, glabrous, apices obtuse to acute;

palea keels smooth, usually short- to long-villous, rarely glabrous;

anthers 0.6-1.1 mm, oblong prior to dehiscence, those of the upper 1-2 florets usually vestigial.

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.

= 28.

= 28, 29+-, 42, 62.