Flora of North America species comparison

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

nodes terete, 0-1 exserted.

5-35 cm tall, 0.5-0.9 mm thick, erect or the bases decumbent, with 0(1) exserted nodes.

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 1/7 - 1/3 their length, terete, smooth or sparsely scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 2-4 times blade lengths;

collar margins smooth or scabrous to hispidulous;

ligules of cauline leaves 1-6 mm, colorless, translucent, smooth or scabrous, truncate to acute, ligules of the innovations 1-2.5 mm;

innovation blades similar to the cauline blades, 1.5-3 mm wide, involute, thick, frequently somewhat arcuate, abaxial surfaces smooth, adaxial surfaces densely scabrous or hispidulous;

cauline blades becoming only slightly shorter distally, 1.5-3 mm wide, involute, moderately thick, soft to moderately firm, abaxial surfaces smooth, apices narrowly prow-shaped.

extravaginal.

intravaginal.

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.

1-6 cm, erect, narrowly lanceoloid to ovoid, moderately congested, with 6-20(25) spikelets;

nodes with 1-2 branches;

branches 0.5-1.5(2) cm, erect, moderately stout, terete or weakly angled, angles smooth to fairly densely scabrous, with 1-3 spikelets.

5-12 mm, laterally compressed;

florets 2-6;

rachilla internodes smooth, infrequently sparsely puberulent.

6-8(12) mm, lengths to 3.5 times widths, broadly lanceolate, laterally compressed, not sexually dimorphic, lustrous;

florets 2-5;

rachilla internodes smooth.

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.

subequal, isomorphic, lanceolate to broadly lanceolate, thin, lustrous, distinctly keeled, keels smooth or sparsely scabrous;

lower glumes shorter than the adjacent lemmas, 3-veined;

calluses glabrous;

lemmas 5-8 mm, lanceolate, distinctly keeled, thinly membranous, smooth or sparsely finely scabrous, glabrous, lateral veins moderately prominent, margins glabrous, apices acute;

palea keels coarsely scabrous;

anthers vestigial (0.1-0.2 mm) or 2-4 mm.

= 28, 29+-, 42, 62.

= unknown.