Flora of North America species comparison

35-80 cm, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 1-2 exserted.

2-10(18) cm, erect to spreading;

nodes terete, none exserted.

closed for 1/3-1/4 their length, terete to slightly compressed, at least some proximal sheaths densely retrorsely scabrous, hispidulous, or softly puberulent for the upper 1/4 of their length, bases of basal sheaths glabrous, distal sheath lengths (1.4)1.7-4.6(6.2) times blade lengths;

collars of proximal leaves glabrous or with hairs the same length as those of their sheaths;

ligules 0.5-2 mm, smooth or scabrous, sometimes puberulent, truncate, those of the lower culm and innovation leaves 0.5-1.5 mm, abaxial surfaces scabrous to softly puberulent, truncate;

innovation blades folded or involute, infrequently flat, moderately thick, soft, adaxial surfaces usually densely scabrous to hispidulous;

cauline blades 2-3.5 mm wide, flat or folded, smooth or sparsely scabrous, glabrous or hispidulous, apices narrowly to broadly prow-shaped, blades gradually reduced distally or the middle blades longest, flag leaf blades 1-10 cm long.

closed for 1/10 – 1/5 their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths 1.5-7 times blade lengths;

collars smooth, glabrous;

ligules 1-3 mm, milky white, smooth or sparsely scabrous, apices obtuse to acute, ligules of upper innovation leaves shorter than 3 mm;

innovation blades similar to the cauline blades;

cauline blades 1-3.5(4.5) cm long, 0.9-1.8 mm wide, folded, moderately thick, soft, smooth, glabrous, adaxial surfaces infrequently sparsely scabrous, usually with papillae on the long cells (at 100x), apices narrowly prow-shaped, flag leaf blades folded, 1-1.8 mm wide, abaxial surfaces with 7-15 closely spaced, slightly protruding ribs.

mainly extra-vaginal.

all or mainly intravaginal.

5-12(18) cm, erect or nodding, ovoid to pyramidal, loosely contracted to open, with 20-70 spikelets, proximal internodes usually shorter than 3.5 cm;

nodes with 2-5 branches;

branches (1)1.7-6.5 cm, ascending to spreading or reflexed, lax, terete or weakly angled, sparsely to moderately scabrous, with 2-8(12) spikelets.

1-4(6) cm, erect, ovoid to lanceoloid, contracted, congested, with 9-40 spikelets;

nodes with 1-3 branches;

branches 0.5-1.5 cm, erect, fairly straight, sulcate or angled, angles sparsely to densely scabrous, with 1-7 spikelets;

pedicels shorter than the spikelets.

5.5-10 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic;

florets 2-7;

rachilla internodes smooth or scabrous, glabrous or sparsely to densely hispidulous.

3.5-6 mm long, lengths to 3.5(3.8) times widths, lanceolate, laterally compressed, fairly strongly anthocyanic, not glaucous;

florets 2-3;

rachilla internodes terete, to 1.5 mm, smooth, sometimes sparsely hispidulous.

1/4 - 2/3(3/4) as long as the adjacent lemmas, lanceolate, distinctly keeled;

lower glumes 1-3-veined, 1/4-1/2 as long as the adjacent lemmas;

calluses glabrous;

lemmas 3-6 mm, lanceolate, distinctly keeled, keels and marginal veins glabrous or softly puberulent to short-villous, intercostal regions glabrous or hispidulous, infrequently puberulent, smooth or finely scabrous, lateral veins obscure to moderately prominent, margins glabrous, apices acute;

palea keels scabrous, intercostal regions glabrous;

anthers usually vestigial (0.1-0.2 mm) or aborted late in development and up to 2 mm, rarely normal.

lanceolate, smooth, distinctly keeled, keels sparsely scabrous;

lower glumes shorter than to equaling the lowest lemmas, 3-veined;

upper glumes frequently exceeding the lowest lemmas, exceeded by the upper lemmas;

calluses glabrous;

lemmas 3-4.9 mm, lanceolate, distinctly keeled, thin, smooth or finely scabrous, glabrous or the keels and marginal veins sparsely puberulent proximally, lateral veins obscure, margins glabrous, apices acute;

palea keels scabrous;

anthers 0.6-1.3(1.8) mm.

= 56, 61, 62, 63, 64, 66, 61, 70, ca. 74, 75, 79, 80, 81, 87, 89, 90, 91.

= unknown.