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.

20-60 cm, slender, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 1-2 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 from 9/10 their length to their entire length, terete, smooth or sparsely scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 0.18-0.8 times blade lengths;

collars smooth, glabrous;

ligules 3-6 mm, scabrous, acute to acuminate;

innovation blades similar to the cauline blades;

cauline blades gradually reduced in length distally, 1.5-2.5 mm wide, flat, thin, soft, smooth or sparsely scabrous, primarily over the veins, apices narrowly to broadly prow-shaped, flag leaf blades 8-12 cm.

intravaginal or intra- and extravaginal.

extravaginal, initiated as pinkish to purplish fleshy buds that persist as sets of short scales at the nodes of rhizomes and the proximal culm nodes, drying brownish and flabelliform after the shoots develop.

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.

4-15 cm, erect, ovoid, sparse, with fewer than 15(20) spikelets;

nodes with 1-2 branches;

branches 1-4.5 cm, spreading to reflexed, slender, terete, sparsely to moderately scabrous, with 1-3 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.

5-9 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic;

florets 2-6;

rachilla internodes smooth, sparsely hairy, hairs to 0.3 mm.

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.

1/3 – 3/4(4/5) as long as the adjacent lemmas, keels sparsely scabrous;

lower glumes 3-veined;

calluses glabrous or webbed, hairs at least 1-2 mm;

lemmas 4-7 mm, lanceolate, distinctly keeled, keels and marginal veins glabrous or short-villous, lateral veins obscure, glabrous, finely scabrous, intercostal regions glabrous or sparsely softly puberulent, margins glabrous, apices acute;

palea keels scabrous, sometimes softly puberulent at midlength;

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

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

= ca. 58.