Flora of North America species comparison

15-60 cm, erect or spreading, bases bulbous.

6-18 cm, with 0(1) exserted nodes, upper node in the lower 1/3 of the culms.

closed for about 1/4 their length, terete, lowest sheaths with swollen bases;

ligules 1-3 mm, smooth or scabrous, apices obtuse to acute;

blades 1-2.5 mm wide, flat, thin, lax, soon withering.

closed for 1/10 – 1/5 their length, terete, smooth or very sparsely scabrous, distal sheath lengths 0.8-1.8 times blade lengths;

ligules 1.25-2.5 mm, smooth, apices obtuse, often lacerate;

blades thin, sparsely scabrous adaxially, flag leaf blades 1.6-3.8 cm.

intravaginal.

mixed intra- and extra vaginal.

3-12 cm, ovoid;

nodes with 2-5 branches;

branches ascending to spreading, terete, usually smooth or sparsely scabrous, infrequently moderately scabrous.

1.5-3.5 cm, slightly lax, ovoid, contracted to loosely contracted, dense to moderately dense, with 2-6 branches per node;

branches steeply ascending, fairly straight, sulcate or angled, smooth or infrequently the angles sparsely scabrous, not glaucous.

3-5 mm, laterally compressed, usually bulbiferous;

florets 3-7, the basal floret, and sometimes additional florets, normal;

rachilla internodes smooth, glabrous.

laterally compressed;

florets 2-5;

rachilla internodes smooth, glabrous, lower internodes 0.8-1 mm.

keeled, keels scabrous;

lower glumes 3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed or glabrous;

lemmas 3-4 mm, lanceolate, keeled, glabrous or the keels and marginal veins short- to long-villous, intercostal regions glabrous or softly puberulent, apices acute;

paleas scabrous, keels often softly puberulent at midlength;

anthers 1.2-1.5 mm and functional, sometimes aborted late in development, sometimes not developed.

equal, broadly lanceolate, thin;

lower glumes 0.75-1.05 mm wide, 3-veined;

upper glumes 3.7-4.7 mm long, 0.9-1.3 mm wide, lengths 3.7-4.1 times widths;

calluses all glabrous, or some proximal florets within a spikelet sparsely webbed;

lemmas 3.7-4.5 mm, broadly lanceolate, distinctly keeled, thin, keels and marginal veins short- to long-villous, hairs extending 1/3-1/2 the keel length, lateral veins usually glabrous, or infrequently sparsely softly puberulent, intercostal regions glabrous;

palea keels finely scabrous;

anthers 0.8-1.2 mm, poorly formed, sacs not fully maturing, not dehiscing, about 0.1 mm in diameter.

= 14, 21, 28, 39, 42, 45.

= ca. 65, 70.