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.

10-30 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 1/7 – 1/6 their length, terete, bases of basal sheaths glabrous;

ligules 1.5-3 mm;

innovation blades similar to the cauline blades;

cauline blades 1-3 mm wide, involute, moderately thick, soft, abaxial surfaces smooth, adaxial surfaces smooth or sparsely scabrous, apices narrowly prow-shaped.

mainly extravaginal.

intravaginal.

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.

3-6 cm, congested or moderately congested;

nodes with (1)2(3) branches;

branches 1-3(4) cm, erect, terete, smooth or sparsely scabrous.

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

florets 2-5;

rachilla internodes smooth.

5-7 mm, lengths to 3.5 times widths, broadly lanceolate, weakly laterally compressed, fairly drab;

florets 2-4;

rachilla internodes usually 1-1.3 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.

lanceolate, distinctly keeled, keels smooth;

lower glumes 3-veined;

calluses glabrous;

lemmas 3-4.6 mm, lanceolate, distinctly to weakly keeled, evenly and densely strigulose over the proximal 1/3-1/2, hairs mostly about 0.1 mm, some keel hairs to 0.2(0.3) mm, lateral veins obscure, margins broadly scarious, glabrous, apices acute;

palea keels scabrous, softly puberulent at midlength, intercostal regions softly puberulent;

anthers 1.5-1.8 mm.

= 28.

= unknown.