Flora of North America species comparison

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

nodes terete, 0-1 exserted.

10-60 cm.

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.

closed for 1/3 – 2/3 their length, terete, smooth;

ligules 1.5-3.5 mm, smooth or sparsely scabrous;

blades 1.5-4 mm wide, flat, thin, soft, apices broadly prow-shaped.

mainly extravaginal.

mixed intra- and extravaginal.

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.

4-15 cm, nodding, open, with numerous spikelets and 1-2 branches per node;

branches (2)3-7 cm, spreading to reflexed, lower branches usually reflexed, flexuous, usually terete, smooth or sparsely scabrous, with (3)6-18 spikelets.

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

florets 2-5;

rachilla internodes smooth.

4-6 mm, lanceolate to broadly lanceolate, usually partly to wholly purplish, with 3-5 florets;

rachilla internodes shorter than 1 mm, smooth.

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.

narrowly to broadly lanceolate, distinctly keeled, keels smooth or nearly so;

lower glumes 1-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas 2-3.5 mm, lanceolate, partly purple to fairly strongly purple, distinctly keeled, keels and marginal veins short- to long-villous, keels hairy for 2h-ls their length, lateral veins usually sparsely softly puberulent at least on 1 side, lateral veins obscure to moderately prominent, intercostal regions smooth, minutely bumpy, glabrous, apices acute, slightly bronze-colored or not;

palea keels scabrous, usually softly puberulent at midlength;

anthers 0.6-1 mm.

= 28.

= 28.