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.

(5)10-125 cm, terete or weakly compressed;

nodes terete or slightly compressed.

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 from 1/7 their length to their entire length, terete to compressed, smooth or scabrous, glabrous or pubescent;

ligules 0.2-18 mm, milky white or colorless, usually translucent, truncate to acuminate, glabrous or ciliolate;

innovation blades with the adaxial surfaces usually moderately to densely scabrous or hispidulous on and between the veins, sometimes smooth and glabrous;

cauline blades flat, folded, or involute, thin or thick, lax or straight, smooth or scabrous, adaxial surfaces sometimes hairy, apices narrowly to broadly prow-shaped.

mainly extravaginal.

intra- and/or 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.

1-29 cm, contracted to open, usually with fewer than 100 spikelets;

nodes with 1-5 branches;

branches 0.5-18 cm, terete or angled, smooth or scabrous, glabrous or hispidulous.

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

florets 2-5;

rachilla internodes smooth.

3-17 mm, lengths 3.5 times widths, laterally compressed, not sexually dimorphic, not bulbiferous;

florets 2-10(13) mm, normal;

rachilla internodes smooth or scabrous, glabrous or hairy.

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.

distinctly keeled, keels smooth or scabrous;

lower glumes 1, 3(or 5)-veined;

upper glumes 3- or 5-veined;

calluses terete or slightly laterally compressed, glabrous, webbed, or with a crown of hairs;

lemmas 2.6-11 mm, lanceolate, distinctly keeled, keels, veins, and intercostal regions glabrous or hairy, 5-7(11)-veined;

palea keels scabrous, glabrous or with hairs at midlength;

anthers 3, vestigial (0.1-0.2 mm) or 1.3-4.5(5) mm.

= 28.