Flora of North America species comparison

30-80 cm, mostly erect, smooth below the panicles;

nodes slightly compressed, 2-5 exserted, top node at 1/2 - 3/4 the culm length.

20-60(100) cm, bases decumbent or sometimes erect, terete, with 1-2 exserted nodes.

closed for 1/10 – 1/5 their length, terete, bases of basal sheaths glabrous, distal sheath lengths 0.45-1 (1.1) times blade lengths;

ligules 0.2-0.8(1) mm, sparsely to densely scabrous, apices truncate, minutely ciliolate;

blades 0.8-3 mm wide, mostly flat, appressed, abruptly ascending to spreading, straight or somewhat lax, apices narrowly prow-shaped.

closed for 1/10 – 1/5(1/4) their length, terete, bases of basal sheaths glabrous;

ligules 2-5 mm, milky white, smooth or sparsely scabrous, acute to acuminate;

innovation blades similar in texture and shape to the cauline blades;

cauline blades not greatly reduced upwards, 1.5-4(5) mm wide, flat or folded, thin, lax, smooth or sparsely scabrous, apices narrowly prow-shaped.

all or mostly extravaginal.

mostly extravaginal, some intravaginal.

7-16(20) cm, lengths usually 2.5-4 times widths at maturity, usually erect, lax in shade forms, narrowly lanceoloid to ovoid, slightly to moderately congested;

nodes with 2-5 branches;

branches ascending to widely spreading, fairly straight, slender to moderately stout, angled, angles moderately to densely scabrous.

5-18(25) cm, lax, loosely contracted to open, sparse, with 20-65 spikelets and usually 2(7) branches per node;

branches 3-15 cm, ascending to spreading, angled, angles finely to coarsely, sparsely to fairly densely scabrous, infrequently smooth, with 3-10(15) spikelets in the distal 1/2.

3-8 mm, lengths 2.5-3.5 times widths, narrowly lanceolate to lanceolate, laterally compressed, usually not glaucous;

florets (1)2-5;

rachilla internodes usually shorter than 1 mm, smooth, muriculate, or scabrous, usually puberulent, infrequently hispidulous or glabrous.

6-10 mm, lengths 3-3.6 times widths, lanceolate to narrowly ovate, laterally compressed, sometimes bulbiferous, drab, often slightly glaucous;

florets 3-4(7), normal or bulb-forming;

rachilla internodes 1.2-2 mm, slightly dorsally compressed, smooth or sparsely muriculate.

subulate to narrowly lanceolate, distinctly keeled, keels smooth or sparsely scabrous, apices sharply acute to acuminate;

lower glumes 3-veined, long-tapered to a slender point, lengths 6.4-11 times widths;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed, hairs sparse, often short;

lemmas 2.4-4 mm, proximal lemma widths less than 1/5 times lengths, narrowly lanceolate to lanceolate, distinctly keeled, keels and marginal veins short-villous, lateral veins glabrous, obscure, intercostal regions smooth or muriculate, glabrous, margins glabrous, apices acute, usually partially bronze-colored;

palea keels scabrous, intercostal regions glabrous;

anthers 0.8-1.9 mm.

subequal, lanceolate to broadly lanceolate, dull, frequently glaucous, obtuse to acute;

lower glumes 3-veined;

upper glumes (3.7)4.1-6.5 mm;

calluses usually crowned with 0.2-2 mm hairs, sometimes glabrous;

lemmas 4-6 mm, lanceolate, distinctly compressed, distinctly keeled, keels, marginal veins, and sometimes the lateral veins short- to long-villous, hairs extending for 3/4 of the keel, intercostal regions glabrous, sparsely puberulent or hispidulous proximally, usually sparsely to moderately densely scabrous distally, hairs distinctly shorter than those of the keel and veins, margins weakly inrolled, broadly scarious, glabrous, apices acute;

palea keels scabrous, often softly puberulent at midlength, intercostal regions glabrous or puberulent;

anthers 1.2-2 mm, sometimes aborted late in development or undeveloped.

= 28, 35, 42, 48, 50, 56.

= 42, [81, 84, 86?].