Flora of North America species comparison

23-86 cm tall, 0.8-1.8 mm thick, bases often decumbent.

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

nodes terete, 0-1 exserted.

closed for 1/3 – 1/2 their length;

ligules 0.2-1.9(2.5) mm, smooth or obtuse;

blades (0.5)1-4 mm wide, flat or folded, thin.

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.

mainly pseudointravaginal.

mainly intravaginal, usually some extravaginal.

(5)8-20 cm, erect or lax, broadly pyramidal at maturity, open, sparse, lower axils sometimes sparsely pubescent;

nodes with 1-2(4) branches;

branches 5-12 cm, spreading to reflexed, straight, angled, angles scabrous, with 3-8 spikelets in the distal 1/4-1/3.

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.

3-8.2 mm, laterally compressed;

florets 2-4(6);

rachilla internodes smooth, sparsely softly puberulent.

(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.

distinctly shorter than the adjacent lemmas, distinctly keeled, keels scabrous;

lower glumes subulate to lanceolate, (1)3-veined;

upper glumes lanceolate to broadly lanceolate;

calluses usually glabrous, rarely sparsely and shortly webbed;

lemmas (2.8)3-4.6 mm, lanceolate, distinctly keeled, keels and marginal veins short- to long-villous, hairs extending up 3/4 of the keel, lateral veins prominent, intercostal regions softly puberulent, smooth, apices obtuse, blunt;

palea keels softly puberulent to short-villous for much of their length, apices scabrous;

anthers 1-1.4(2.6) mm.

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.

= 28.

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