Flora of North America species comparison

30-80 cm, mostly erect, smooth below the panicles;

nodes slightly compressed, 2-5 exserted, top node at 1/2 - 3/4 the culm length.

30-90 cm, slender to coarse.

closed for 1/10 – 1/5 their length, terete, bases of basal sheaths glabrous, distal sheath lengths 0.45-1 (1.1) times blade lengths;

ligules 0.2-0.8(1) mm, sparsely to densely scabrous, apices truncate, minutely ciliolate;

blades 0.8-3 mm wide, mostly flat, appressed, abruptly ascending to spreading, straight or somewhat lax, apices narrowly prow-shaped.

closed for 1/20 – 1/10 their length, terete, scabrous, glabrous;

collars smooth to scabrous;

ligules 0.5-4(6) mm, scabrous, apices truncate to acute, entire or lacerate;

innovation blades 15-30 cm;

cauline blades 1-4 mm wide, involute or rarely flat, moderately thick and firm, both surfaces sparsely to densely antrorsely scabrous, apices narrowly prow-shaped, flag leaf blades usually longer than their sheaths.

all or mostly extravaginal.

intra-vaginal.

7-16(20) cm, lengths usually 2.5-4 times widths at maturity, usually erect, lax in shade forms, narrowly lanceoloid to ovoid, slightly to moderately congested;

nodes with 2-5 branches;

branches ascending to widely spreading, fairly straight, slender to moderately stout, angled, angles moderately to densely scabrous.

(7)10-30 cm, erect, pyramidal, open, with 2-5 branches per node;

branches 2-8(15) cm, spreading, straight, angled, angles moderately to densely scabrous, sometimes densely scabrous all over, with 10-30 spikelets.

3-8 mm, lengths 2.5-3.5 times widths, narrowly lanceolate to lanceolate, laterally compressed, usually not glaucous;

florets (1)2-5;

rachilla internodes usually shorter than 1 mm, smooth, muriculate, or scabrous, usually puberulent, infrequently hispidulous or glabrous.

4-7 mm, lanceolate, laterally compressed;

florets 2-5;

rachilla internodes 0.8-1.5 mm, smooth or scabrous, sometimes sparsely hispidulous.

subulate to narrowly lanceolate, distinctly keeled, keels smooth or sparsely scabrous, apices sharply acute to acuminate;

lower glumes 3-veined, long-tapered to a slender point, lengths 6.4-11 times widths;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed, hairs sparse, often short;

lemmas 2.4-4 mm, proximal lemma widths less than 1/5 times lengths, narrowly lanceolate to lanceolate, distinctly keeled, keels and marginal veins short-villous, lateral veins glabrous, obscure, intercostal regions smooth or muriculate, glabrous, margins glabrous, apices acute, usually partially bronze-colored;

palea keels scabrous, intercostal regions glabrous;

anthers 0.8-1.9 mm.

sparsely to rarely densely scabrous;

lower glumes 1-3-veined;

calluses usually glabrous, rarely sparsely short-webbed;

lemmas 2.5-3.5 mm, lanceolate, distinctly keeled, smooth or sparsely to densely scabrous, keels and marginal veins glabrous or softly puberulent or short- to long-villous, lateral veins moderately prominent to prominent, intercostal regions usually glabrous, infrequently sparsely softly puberulent, apices acute;

palea keels scabrous;

anthers aborted late in development, or 2.2-2.5 mm.

= 28, 35, 42, 48, 50, 56.

= 28+1, 28-29+11.