Flora of North America species comparison

10-60(70) cm tall, 0.5-1.8 mm thick, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 0-2 exserted.

spindly to stout, terete or weakly to strongly compressed;

nodes 0-5, exserted.

closed for 1/4-3/4 their length, terete, smooth or scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 1.6-10 times blade lengths;

collars smooth or scabrous, glabrous;

ligules of cauline leaves 1-3(6) mm, smooth or scabrous, truncate to acute, ligules of the innovation leaves 0.2-0.5(2.5) mm, scabrous, usually truncate;

innovation blades sometimes distinctly different from the cauline blades, 0.5-2 mm wide, involute, moderately thick, moderately firm, adaxial surfaces usually densely scabrous or hispidulous to softly puberulent, infrequently nearly smooth and glabrous;

cauline blades subequal or the midcauline blades longest or the blades gradually reduced in length distally, 0.5-3 mm wide, flat, folded, or involute, usually thin, usually withering, abaxial surfaces smooth or scabrous, apices narrowly to broadly prow-shaped, flag leaf blades 0.5-5(6) cm.

terete or weakly to strongly compressed, closed only at the base or up to full length, fusion of the margins not extended by a hyaline membrane, basal sheaths usually glabrous, rarely sparsely retrorsely strigose, hairs about 0.1 mm;

ligules 0.1-18 mm, thinly membranous and white to milky white or hyaline, truncate to acuminate, entire or erose to lacerate, smooth or ciliolate;

blades flat, folded, or involute, thin to thick, smooth or sparsely to densely scabrous, adaxial surfaces glabrous or hairy, hispidulous or puberulent, apices narrowly to broadly prow-shaped.

intravaginal or intra- and extravaginal.

intra- and/or extravaginal or pseudointravaginal.

2-10(12) cm, usually erect, contracted or loosely contracted, narrowly lanceoloid to ovoid, congested or moderately congested, with 10-100 spikelets and 1-3(5) branches per node;

branches 0.5-4(5) cm, erect or steeply ascending, fairly straight, slender to stout, terete to angled, smooth or scabrous, with 1-15 spikelets.

1-41 cm, erect to nodding or lax, tightly contracted to open, with 1-100+ spikelets;

branches 0.5-20 cm, erect to reflexed, terete or angled, smooth or sparsely to densely scabrous, usually glabrous, rarely hispidulous, with 1 to many spikelets.

(3)4-10 mm, lengths to 3 times widths, broadly lanceolate to narrowly ovate, laterally compressed, not sexually dimorphic;

florets 2-6;

rachilla internodes 0.5-1.2 mm, smooth or scabrous.

2-12 mm, subterete to strongly laterally compressed, sometimes bulbiferous;

florets (1)2-8(13);

rachilla internodes smooth or scabrous, glabrous or pubescent.

lanceolate, distinctly keeled;

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

calluses glabrous or diffusely webbed, hairs less than 1/4 the lemma length;

lemmas (3)4-7 mm, lanceolate to broadly lanceolate, distinctly keeled, membranous to thinly membranous, smooth or sparsely to densely scabrous, glabrous or the keels and/or marginal veins puberulent proximally, lateral veins obscure to prominent, margins glabrous, apices acute;

palea keels scabrous, intercostal regions glabrous;

anthers vestigial (0.1-0.2 mm), aborted late in development, or 2-3.5 mm.

shorter than to slightly exceeding the adjacent lemmas, weakly to distinctly keeled, smooth or scabrous;

calluses blunt, usually terete or slightly laterally compressed, sometimes slightly dorsally compressed, glabrous, dorsally webbed, diffusely webbed, or with a crown of hairs;

lemmas 1.7-11 mm, rounded to weakly or distinctly keeled, thinly membranous to chartaceous, glabrous or hairy on the keel and veins, sometimes the intercostal regions also hairy, 5-7(11)-veined, margins smooth or scabrous, glabrous, apices obtuse to acuminate;

palea keels usually scabrous, infrequently smooth, glabrous or with hairs;

anthers (1-2)3, 0.1-4.5(5) mm.

= 28, 28+11, 56, 56+11, 59, ca. 70.