Flora of North America species comparison

15-70 cm, sometimes stout, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 0-1 exserted.

10-33(45) cm, usually decumbent, terete;

nodes terete, 0(1) exserted.

closed for about 1/3 their length, terete, smooth or scabrous, glabrous or occasionally retrorsely pubescent, bases of basal sheaths glabrous, distal sheath lengths usually (5)9+ times blade lengths;

collars smooth or scabrous, glabrous or hispidulous;

ligules 0.2-18 mm, smooth or scabrous, decurrent or not, apices truncate to acuminate, ciliolate or glabrous;

innovation blades usually moderately to densely scabrous or hispidulous on and between the veins, infrequently nearly smooth and glabrous;

cauline blades strongly reduced in length distally, (0.5)1-3(4) mm wide, usually involute, moderately thick and firm, infrequently moderately thin, abaxial surfaces usually smooth, infrequently scabrous, apices narrowly prow-shaped, steeply reduced in length distally along the culm, flag leaf blades often absent or very reduced, sometimes to 1(3) cm.

closed for 1/7 – 1/5(1/3) their length, terete, usually lustrous, bases of basal sheaths glabrous;

ligules (1.5)2-7 mm, smooth or sparsely scabrous, margins usually decurrent, apices obtuse to acuminate;

innovation blades similar in texture and shape to those of the culms;

cauline blades 2-9 cm, gradually increasing or decreasing in length upwards, 1.5-3 mm wide, folded to involute, moderately thick, soft, abaxial surfaces smooth, adaxial surfaces smooth or somewhat scabrous, usually glabrous, infrequently sparsely hispidulous, apices narrowly prow-shaped.

mainly intravaginal, usually some extravaginal.

extra- and intravaginal.

2-12(30) cm, erect, contracted, narrowly lanceoloid to ovoid, congested, frequently with 100+ spikelets;

nodes with 1-2 branches;

branches 1-8 cm, erect, terete to weakly angled, smooth or scabrous, with 3-15(25) spikelets.

2.5-6(12) cm, erect, narrowly lanceolate, contracted or narrowly ovate in some bulbiferous plants, moderately congested, with 7-40 spikelets;

nodes with (1)2(4) branches;

branches 1-3 cm, erect to ascending, straight, sulcate, smooth or sparsely to moderately scabrous, with 1-10 spikelets in the distal 1/3 – 2/3.

(3)4-8(12) mm, lengths to 3 times widths, broadly lanceolate to ovate, laterally compressed, not sexually dimorphic;

florets 2-7(13);

rachilla internodes 0.8-1.3 mm, smooth, glabrous or hairy, hairs to 0.3 mm.

4.8-7.4 mm, lengths 3.5-4 times widths, lanceolate, weakly laterally compressed, sometimes bulbiferous, lustrous;

florets (2)3-5(6), normal or bulb-forming;

rachilla internodes 0.8-2 mm, smooth, sometimes sparsely hispidulous.

lanceolate, distinctly keeled;

lower glumes 1-3-veined, distinctly shorter than the lowest lemmas;

calluses glabrous;

lemmas 3-6 mm, lanceolate, distinctly keeled, keels, marginal veins, and lateral veins glabrous or short- to long-villous or softly puberulent, lateral veins moderately prominent, intercostal regions softly puberulent or glabrous, smooth or sparsely scabrous, margins glabrous, apices acute;

palea keels scabrous, sometimes softly puberulent or long-villous at midlength, hairs to 0.4+ mm;

anthers vestigial (0.1-0.2 mm) or 2-3 mm.

mostly broadly scarious, somewhat lustrous, keels indistinct, smooth or sparsely scabrous distally;

lower glumes 3-veined;

upper glumes frequently exceeding the lowest lemmas;

calluses glabrous or with a crown of hairs, hairs to 2 mm;

lemmas (3.3)3.5-7 mm, lanceolate, usually weakly keeled, more or less evenly and somewhat loosely to densely hairy over the proximal 1/3-1/2, hairs usually longer than 0.5 mm, sparsely scabrous in the middle 1/3, smooth distally, lateral veins obscure, margins weakly inrolled, broadly scarious, glabrous, apices long-scarious, acute to shortly obtuse, often erose, often bronze-colored below the apices;

palea keels sparsely scabrous, softly puberulent at midlength, intercostal regions softly puberulent;

anthers usually all aborted late in development and 0.8-1.8 mm, infrequently well developed and 2-2.8 mm.

= 28+11, 56, 56-58, 58-64.

= 63, 70.