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.

30-100 cm, erect, terete, with 0(1) exserted nodes.

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.

closed for 1/10(1/8) their length, terete, bases of basal sheaths glabrous, distal sheath lengths 1.5-5 times blade lengths;

ligules 4-6 mm, scabrous, obtuse to acute;

innovation blades similar to the cauline blades;

cauline blades 1-3 mm wide, folded to involute, thick, fairly firm, pale green, abaxial surfaces scabrous, apices narrowly prow-shaped.

intravaginal or intra- and extravaginal.

intravaginal.

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.

5-18(21) cm, erect, narrowly to broadly lanceoloid, loosely contracted, congested, with 40-100+ spikelets;

nodes with 2-3(5) branches;

branches 3-10 cm, erect to ascending, straight, angles densely scabrous, with 5-27 spikelets in the distal 1/2.

(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.

(4)4.5-7 mm, lengths 3-3.5 times widths, lanceolate, laterally compressed, drab;

florets 3-5;

rachilla internodes usually shorter than 1 mm, smooth.

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.

lanceolate, slightly unequal, pale, distinctly keeled, keels sparsely scabrous;

lower glumes 3-veined;

calluses glabrous, rarely with a crown of hairs, hairs to 0.1 mm;

lemmas 3-4 mm, lanceolate, distinctly keeled, finely scabrous, usually glabrous, keels and marginal veins rarely sparsely puberulent proximally, lateral veins obscure to moderately prominent, intercostal regions muriculate, margins glabrous, apices acute;

paleas scabrous over the keels;

anthers 1.2-1.8 mm.

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

= 42.