Flora of North America species comparison

10-55 cm, very slender, weak.

(25)32-125 cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed;

nodes terete or slightly compressed, 1-2(3) exserted.

closed for 1/4 - 3/5 their length, terete, smooth or sparsely scabrous, margins not ciliate;

ligules 0.5-2 mm, smooth or sparsely scabrous, truncate;

blades 0.8-2 mm wide, flat, thin, soft, apices narrowly prow-shaped.

closed for (2/5)1/2 – 9/10 their length, compressed, distinctly keeled, keels winged, wing to 0.5 mm wide, smooth or sparsely to infrequently densely scabrous, glabrous or infrequently retrorsely pubescent, bases of basal sheaths glabrous, distal sheath lengths 0.7-1.6 times blade lengths;

collars with vestiture similar to the sheaths;

ligules 2-4.5 mm, smooth or scabrous, glabrous or softly puberulent, obtuse to acute;

innovation blades similar to the cauline blades;

cauline blades (1.5)2-5.5 mm wide, flat, lax, smooth or sparsely scabrous mainly over the veins, apices broadly prow-shaped, flag leaf blades 6-20 cm.

mostly extravaginal.

mainly extravaginal.

3-8(12) cm, lax, open, sparse;

nodes with 1-2(3) branches;

branches (2)3-7 cm, spreading to reflexed, capillary, angled, angles scabrous.

(8)13-29 cm, erect, usually narrowly pyramidal, open, sparse, with 30-100 spikelets, proximal internodes usually 4+ cm, with (1)2-4(5) branches per node;

branches 2.5-18 cm, spreading to eventually reflexed, fairly flexuous, terete to weakly angled, sparsely to moderately scabrous, with 3-34 spikelets.

3.2-5.2 mm, laterally compressed, broadly lanceolate to ovate;

florets 2-3(5);

rachilla internodes smooth, glabrous.

3-8 mm, lengths 3.5 times widths, laterally compressed, not sexually dimorphic;

florets 2-8;

rachilla internodes 1+ mm, smooth, glabrous.

narrowly lanceolate to lanceolate, thin, distinctly keeled, keels scabrous;

lower glumes 1-3-veined;

upper glumes shorter than or subequal to the adjacent lemmas;

calluses sparsely webbed;

lemmas 2.5-4 mm, lanceolate, green, distinctly keeled, keels and marginal veins short-villous, extending 2/3 – 4/5 the keel length, lateral veins fairly prominent, intercostal regions glabrous, apices obtuse to broadly acute, white, faintly bronze-colored or not;

palea keels scabrous;

anthers 0.2-0.8 mm.

narrowly lanceolate, distinctly keeled;

lower glumes 1.6-3.5 mm, 1(3)-veined, 1/2-1/3 as long as the adjacent lemmas;

upper glumes 2.2-4.9 mm;

calluses webbed, hairs over 1/2 the lemma length;

lemmas 2.6-5 mm, lanceolate, distinctly keeled, keels and marginal veins long-villous, extending 1/2 - 2/3 the keel length, 1/3-1/2 the marginal vein length, lateral veins sometimes short-villous, the lateral veins obscure to moderately prominent, intercostal regions usually sparsely softly puberulent, margins glabrous, apices acute;

palea keels scabrous, rarely softly puberulent at midlength;

anthers vestigial (0.1-0.2 mm) or (1.3)2-3 mm.

= unknown.

= 28, 28+1.