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.

10-40 cm.

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.

intravaginal or intra- and extravaginal.

intravaginal.

mostly basal;

sheaths closed for 1/8 – 2/7 their length, terete, basal sheaths persistent, overlapping, bases usually not swollen;

ligules of innovations 1-2(3) mm, those of the upper cauline leaves to 4(5) mm, milky white, smooth, glabrous, obtuse;

blades of innovations widely spreading, persisting through the season, blades of cauline leaves 1-5(12) cm long, 2-4.5 mm wide, flat, moderately thick, soft, straight, smooth or the margins sparsely scabrous, apices broadly prow-shaped, blades of upper cauline leaves much reduced in length.

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.

2-6(8) cm, erect, ovoid to pyramidal, open or loosely contracted at maturity, fairly congested;

nodes with 1-2 branches, lowest internodes 0.6-1(1.5) cm;

branches 1-3(4) cm, ascending to spreading, straight, terete, usually smooth or sparsely scabrous, rarely moderately densely scabrous;

pedicels divaricate, shorter than the 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.

3.9-6.2 mm, ovate, lengths 1.5-2.5 times widths, laterally compressed, plump, sometimes bulbiferous;

florets 3-7, usually normal;

rachilla internodes 0.5-0.8 mm, smooth, glabrous or sparsely softly puberulent to short-villous.

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.

broadly lanceolate to narrowly ovate, keeled, keels sparsely scabrous;

lower glumes 3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses glabrous;

lemmas 3-5 mm, broadly lanceolate, keeled, keels and marginal veins short- to long-villous, lateral veins moderately prominent, intercostal regions sparsely to moderately short-villous, apices acute;

palea keels softly puberulent to short-villous over most of their length, apices scabrous;

anthers 1.3-2.3 mm.

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

= 22, 23, 24,25, 26, 27, 28, 28+11, 30, 31, 32, 32+1, 33, 34, 35, 36, 37, 39, 40+1, 41, 42, ca. 43, 44, 46, ca. 48, 56.