Flora of North America species comparison

23-86 cm tall, 0.8-1.8 mm thick, bases often decumbent.

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

closed for 1/3 – 1/2 their length;

ligules 0.2-1.9(2.5) mm, smooth or obtuse;

blades (0.5)1-4 mm wide, flat or folded, thin.

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.

mainly pseudointravaginal.

mixed intra- and extra vaginal.

(5)8-20 cm, erect or lax, broadly pyramidal at maturity, open, sparse, lower axils sometimes sparsely pubescent;

nodes with 1-2(4) branches;

branches 5-12 cm, spreading to reflexed, straight, angled, angles scabrous, with 3-8 spikelets in the distal 1/4-1/3.

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.

3-8.2 mm, laterally compressed;

florets 2-4(6);

rachilla internodes smooth, sparsely softly puberulent.

laterally compressed;

florets 2-5;

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

distinctly shorter than the adjacent lemmas, distinctly keeled, keels scabrous;

lower glumes subulate to lanceolate, (1)3-veined;

upper glumes lanceolate to broadly lanceolate;

calluses usually glabrous, rarely sparsely and shortly webbed;

lemmas (2.8)3-4.6 mm, lanceolate, distinctly keeled, keels and marginal veins short- to long-villous, hairs extending up 3/4 of the keel, lateral veins prominent, intercostal regions softly puberulent, smooth, apices obtuse, blunt;

palea keels softly puberulent to short-villous for much of their length, apices scabrous;

anthers 1-1.4(2.6) mm.

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.

= 28.

= ca. 65, 70.