Flora of North America species comparison

25-90 cm.

15-60 cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed;

nodes terete, 0-1 exserted.

closed for 1/2 - 3/4 their length, smooth or sparsely scabrous, margins not ciliate;

ligules 0.3-2.1 mm, smooth or sparsely scabrous, truncate to obtuse, ciliolate;

blades 0.6-3.5 mm wide, flat.

closed for about 1/2 their length, slightly compressed, distinctly keeled, glabrous, bases of basal sheaths glabrous, distal sheath lengths 4-60 times blade lengths;

collars of proximal leaves usually retrorsely scabrous or pubescent distally and about the throat;

ligules 0.5-4 mm, smooth or scabrous, apices truncate to acute;

innovation blades similar to the cauline blades;

cauline blades 1-4 mm wide, usually flat, sometimes slightly folded, smooth or sparsely scabrous, primarily over the veins, apices broadly prow-shaped, blades steeply reduced in length distally, flag leaf blades 0.2-3(6) cm.

mainly pseudointravaginal.

mainly extravaginal.

7.5-15(18) cm, lax, pyramidal, open, sparse;

nodes with 1-3(5) branches;

branches 3-8 cm, ascending, straight to spreading, angled, angles prominent, scabrous.

5-15 cm, erect or lax, pyramidal, open, sparse, with 20-80 spikelets, proximal internodes usually 3+ cm;

nodes usually with 2 branches;

branches (2)3-7(10) cm, spreading to reflexed, straight, angled, angles scabrous, with 2-8(10) spikelets.

4-6.5 mm, laterally compressed;

florets 2-5;

rachilla internodes to 1 mm, smooth, glabrous.

5-8 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic;

florets 2-5;

rachilla internodes smooth.

1/2-1/3 the length of the adjacent lemmas, distinctly keeled, keels scabrous;

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

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas (2.5)3.2-4.7 mm, lanceolate, green, distinctly keeled, keels and marginal veins long-villous, hairs extending up almost the whole keel length, lateral veins prominent, intercostal regions smooth, minutely bumpy, usually glabrous, rarely sparsely softly puberulent, apices acute, blunt, or pointed, white, not bronze;

palea keels softly puberulent at midlength, apices scabrous;

anthers (0.5)0.8-1.2(1.5) mm.

narrowly lanceolate to lanceolate, distinctly keeled;

lower glumes 1-3-veined;

calluses webbed, hairs over 1/3 the lemma length;

lemmas 3-6 mm, lanceolate, distinctly keeled, keels and marginal veins sparsely short- to long-villous, lateral veins moderately prominent, intercostal regions glabrous or the upper florets in the spikelets softly puberulent, margins glabrous, apices acute;

palea keels scabrous, softly puberulent at midlength;

anthers vestigial (0.1-0.2 mm) or 2-3.5 mm.

= 28.

= 28.