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.

5-35 cm tall, 0.5-0.9 mm thick, erect or the bases decumbent, with 0(1) exserted nodes.

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 1/7 - 1/3 their length, terete, smooth or sparsely scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 2-4 times blade lengths;

collar margins smooth or scabrous to hispidulous;

ligules of cauline leaves 1-6 mm, colorless, translucent, smooth or scabrous, truncate to acute, ligules of the innovations 1-2.5 mm;

innovation blades similar to the cauline blades, 1.5-3 mm wide, involute, thick, frequently somewhat arcuate, abaxial surfaces smooth, adaxial surfaces densely scabrous or hispidulous;

cauline blades becoming only slightly shorter distally, 1.5-3 mm wide, involute, moderately thick, soft to moderately firm, abaxial surfaces smooth, apices narrowly prow-shaped.

all or mostly extravaginal.

intravaginal.

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.

1-6 cm, erect, narrowly lanceoloid to ovoid, moderately congested, with 6-20(25) spikelets;

nodes with 1-2 branches;

branches 0.5-1.5(2) cm, erect, moderately stout, terete or weakly angled, angles smooth to fairly densely scabrous, with 1-3 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.

6-8(12) mm, lengths to 3.5 times widths, broadly lanceolate, laterally compressed, not sexually dimorphic, lustrous;

florets 2-5;

rachilla internodes smooth.

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.

subequal, isomorphic, lanceolate to broadly lanceolate, thin, lustrous, distinctly keeled, keels smooth or sparsely scabrous;

lower glumes shorter than the adjacent lemmas, 3-veined;

calluses glabrous;

lemmas 5-8 mm, lanceolate, distinctly keeled, thinly membranous, smooth or sparsely finely scabrous, glabrous, lateral veins moderately prominent, margins glabrous, apices acute;

palea keels coarsely scabrous;

anthers vestigial (0.1-0.2 mm) or 2-4 mm.

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

= unknown.