Flora of North America species comparison

25-120 cm, erect or the bases decumbent, sometimes branching above the base, terete or weakly compressed, scabrous below the panicle;

nodes terete or slightly compressed, proximal nodes often slightly swollen, uppermost node at or above (73)72 the culm length.

(10)15-120 cm, slender to stout, erect or the bases slightly decumbent, terete or weakly compressed;

nodes terete, 0-2 exserted.

closed for 1/10 – 1/5 their length, slightly compressed, glabrous or sparsely retrorsely scabrous, bases of basal sheaths glabrous, distal sheath lengths 0.7-2.2 times blade lengths;

ligules (1)1.5-6 mm, smooth or sparsely to moderately scabrous, apices obtuse to acute, frequently lacerate, usually minutely ciliolate;

blades 1.5-8 mm wide, flat, usually several per culm, steeply ascending or spreading to 80°, often lax distally, apices narrowly prow-shaped.

closed for 1/10-1/4 their length, terete, smooth or scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths (0.95)1.5-7(15) times blade lengths;

collars smooth or scabrous, glabrous;

ligules 0.5-6(10) mm, smooth or scabrous, truncate to acuminate, ligules of innovation leaves similar to those of the cauline leaves or shorter and truncate;

innovation blades similar to the cauline blades;

cauline blades gradually reduced in length upwards or the middle blades longest, 0.4-3(5) mm wide, flat, folded, or involute, thin, soft, and soon withering to thick, firm, and persisting, smooth or scabrous mainly over the veins, glabrous, apices narrowly prow-shaped, flag leaf blades 0.8-10(17) cm.

extravaginal or mixed extra- and intravaginal.

intra- and extra vaginal.

(9)13-30(41) cm, lengths 73-72 times widths at maturity, lax, eventually open, sparsely to moderately congested, with 25-100+ spikelets;

nodes with 2-9 branches;

branches 4-15 cm, 3/10 – 1/2 the panicle length, initially erect, eventually widely spreading to slightly reflexed, fairly straight, slender, angles densely scabrous.

2-25(30) cm, erect or somewhat lax, narrowly lanceoloid to ovoid, usually contracted, more or less open at anthesis, infrequently remaining open at maturity, green or anthocyanic, sometimes glaucous, usually moderately congested, with 10-100+ spikelets;

nodes usually with 1-3 branches;

branches (0.5)1-8(10) cm, usually erect or ascending, infrequently spreading at maturity, terete to weakly angled, usually sparsely to densely scabrous on and between the angles, with (1)2-20(60+) spikelets in the distal 1/2-1/3.

3-5 mm, lengths 3-3.5 times widths, narrowly to broadly lanceolate, laterally compressed;

florets (1)2-5;

rachilla internodes mostly shorter than 1 mm, usually muriculate, sometimes smooth, rarely sparsely hispidulous.

(4)5-10 mm, lengths (3.8)4-5 times widths, usually narrowly lanceolate, subterete to weakly laterally compressed, drab, green or strongly anthocyanic, sometimes glaucous;

florets (2)3-5(10);

rachilla internodes usually 1-2 mm, terete or slightly dorsally compressed, smooth or muriculate to scabrous.

subulate to lanceolate, distinctly keeled, keels smooth or sparsely scabrous;

lower glumes with lengths 6.4-10 times widths, 3-veined, long-tapered to a slender point;

calluses sparsely to moderately densely webbed, hairs (1/2)2/3 the lemma length;

lemmas 2-3 mm, narrowly lanceolate to lanceolate, distinctly keeled, keels straight or gradually arched, usually abruptly inwardly arched at the junction of the scarious apices, keels and marginal veins short-villous, lateral veins obscure, intercostal regions muriculate, glabrous, margins distinctly inrolled, glabrous, apices obtuse or acute, usually partially bronze-colored, frequently incurved and blunt with a short, hyaline margin;

palea keels scabrous, intercostal regions glabrous;

anthers 1.3-1.8 mm.

broadly lanceolate, keels indistinct;

lower glumes 3-veined;

calluses glabrous or with a crown of hairs, hairs 0.1-0.5(2) mm, crisp or slightly sinuous;

lemmas 3.5-6 mm, lanceolate to narrowly lanceolate or slightly oblanceolate, usually weakly keeled, glabrous or the keels and marginal veins softly puberulent to short-villous, intercostal regions smooth or scabrous, glabrous, short-villous, crisply puberulent or softly puberulent over the basal 2/3, hairs usually 0.1-0.5 mm, hairs of the keels and veins frequently similar in length to those between the veins, usually not or only slightly denser and extending further towards the apices, lateral veins obscure, margins strongly inrolled below, broadly scarious above, glabrous, apices obtuse to broadly acute, blunt, or pointed;

palea keels scabrous, glabrous or softly puberulent to short-villous at midlength;

anthers 1.5-3 mm.

= 28, 30, 32, 35, 42, 56, 84.

= 42, 44+f, ca. 48, 56, ca. 62, 63, ca. 66, ca. 68, 70, ca.72, ca. 74, 78, ca. 80, 81, 82, ca. 83, 84-86, ca. 87, ca. 88, ca. 90, ca. 91, 93, ca. 94, ca. 97, ca. 98, ca. 99, 100, 104, 105-106.