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.

10-40 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.

mainly extravaginal.

intravaginal.

mostly basal;

sheaths closed for 1/8 – 2/7 their length, terete, basal sheaths persistent, overlapping, bases usually not swollen;

ligules of innovations 1-2(3) mm, those of the upper cauline leaves to 4(5) mm, milky white, smooth, glabrous, obtuse;

blades of innovations widely spreading, persisting through the season, blades of cauline leaves 1-5(12) cm long, 2-4.5 mm wide, flat, moderately thick, soft, straight, smooth or the margins sparsely scabrous, apices broadly prow-shaped, blades of upper cauline leaves much reduced in length.

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.

2-6(8) cm, erect, ovoid to pyramidal, open or loosely contracted at maturity, fairly congested;

nodes with 1-2 branches, lowest internodes 0.6-1(1.5) cm;

branches 1-3(4) cm, ascending to spreading, straight, terete, usually smooth or sparsely scabrous, rarely moderately densely scabrous;

pedicels divaricate, shorter than the spikelets.

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

florets 2-5;

rachilla internodes smooth.

3.9-6.2 mm, ovate, lengths 1.5-2.5 times widths, laterally compressed, plump, sometimes bulbiferous;

florets 3-7, usually normal;

rachilla internodes 0.5-0.8 mm, smooth, glabrous or sparsely softly puberulent to short-villous.

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.

broadly lanceolate to narrowly ovate, keeled, keels sparsely scabrous;

lower glumes 3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses glabrous;

lemmas 3-5 mm, broadly lanceolate, keeled, keels and marginal veins short- to long-villous, lateral veins moderately prominent, intercostal regions sparsely to moderately short-villous, apices acute;

palea keels softly puberulent to short-villous over most of their length, apices scabrous;

anthers 1.3-2.3 mm.

= 28.

= 22, 23, 24,25, 26, 27, 28, 28+11, 30, 31, 32, 32+1, 33, 34, 35, 36, 37, 39, 40+1, 41, 42, ca. 43, 44, 46, ca. 48, 56.