Flora of North America species comparison

20-95 cm tall, 0.8-1.5 mm thick.

20-65 cm, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 1-2 exserted.

closed for 1/3-2/3 their length;

ligules 0.2-3(4) mm, smooth or sparsely scabrous, truncate to obtuse;

blades 1-3.6 (6) mm wide, flat, thin, lax, veins prominent.

closed for 2/3 – 9/10 their length, terete to slightly compressed, smooth or sparsely scabrous, sometimes hairy, hairs about 0.15 mm, bases of basal sheaths glabrous, distal sheath lengths (0.7)1-2.2(2.8) times blade lengths;

collars of proximal leaves usually hairy on and near the margins, marginal hairs longer than those of the sheaths;

ligules 0.5-1.5 mm, smooth or scabrous, hairy, hairs about 0.15 mm, truncate to obtuse, those of the lower culm and innovation leaves 0.5-1 mm, scabrous or softly puberulent, truncate;

innovation blades similar to or longer than the cauline blades;

cauline blades 2-4.5 mm wide, usually flat, lax, adaxial surfaces smooth or sparsely scabrous, particularly over the veins, apices broadly prow-shaped, blades gradually reduced in length distally or the middle blades longest, flag leaf blades 3-8 cm long.

mainly pseudointravaginal.

mainly extravaginal.

4-20(24) cm long, less than 1/4 the plant height, lax;

nodes with 1-3 branches;

branches ascending to spreading, lax, angled, angles prominent, scabrous.

8-15 cm, erect or lax, ovoid to pyramidal, open or loosely contracted, sparse, with 25-80 spikelets, proximal internodes 1.8-3.5 cm;

nodes with 3-5 branches;

branches 2.5-8 cm, ascending to spreading, lax, terete to weakly angled, moderately scabrous, with 2-8 spikelets.

3-5.6 mm, laterally compressed;

florets 2-5;

rachilla internodes glabrous, usually shorter than 1 mm.

4-7 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic;

florets 3-8;

rachilla internodes smooth or scabrous, glabrous or sparsely hispidulous.

2/3 – 3/4 as long as the adjacent lemmas, distinctly keeled;

lower glumes 1(3)-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas 2.4-4 mm, lanceolate to broadly lanceolate, distinctly keeled, usually glabrous, bases of marginal veins rarely sparsely softly puberulent, lateral veins prominent, intercostal regions smooth, minutely bumpy, apices obtuse to sharply acute or acuminate;

palea keels scabrous;

anthers 0.4-1.5 mm.

2/3 – 4/5 as long as the adjacent lemmas, lanceolate, distinctly keeled;

lower glumes 1-3(5)-veined;

calluses usually glabrous, rarely minutely webbed;

lemmas 3-4.5 mm, lanceolate, distinctly keeled, keels and marginal veins usually glabrous, infrequently sparsely softly puberulent to short-villous, intercostal regions glabrous or hispidulous, smooth or finely scabrous, margins glabrous, apices acute;

paleas scabrous over the keels, intercostal regions glabrous;

anthers usually 2.5-4 mm, sometimes vestigial (0.1-0.2 mm).

= 28, 28+1.