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.

2-15 cm, prostrate to erect, slender;

nodes terete, usually 1 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.

closed for about 1/3 their length, terete or weakly compressed, smooth;

ligules 0.5-3 mm, smooth, glabrous, decurrent, obtuse to truncate;

blades 1-3(4) mm wide, flat, thin, soft, smooth, margins usually slightly scabrous, apices broadly prow-shaped.

intravaginal or intra- and extravaginal.

intravaginal, sterile shoots common, similar to the culms.

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.

1-6 cm, lengths 1.5-3 times widths, erect;

nodes with 1-2(5) branches;

branches ascending, straight, terete, smooth, with crowded 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.

3-5 mm, laterally compressed;

florets 2-6;

rachilla internodes smooth, glabrous, usually exposed in side view, distal internodes 1/2 - 3/4 the length of tbe distal lemma.

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.

smooth, distinctly keeled, keels smooth;

lower glumes 1-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses glabrous;

lemmas 2-2.5 mm, lanceolate, distinctly keeled, smooth throughout, the keels, marginal and lateral veins crisply puberulent to long-villous, lateral veins prominent, intercostal regions glabrous, margins smooth, glabrous, apices obtuse to acute;

palea keels smooth, short- to long-villous;

anthers 0.1-0.6 mm, more or less spherical to short-elliptical prior to dehiscence, those of the upper 1-2 florets commonly vestigial.

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

= 14.