Flora of North America species comparison

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

50-120 cm.

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.

closed for 1/2 - 3/4 their length, usually sparsely to moderately retrorsely scabrous, margins not ciliate;

ligules 2-3.5 mm, smooth or sparsely scabrous, obtuse to acute;

blades 3-8 mm wide, flat, lax, apices narrowly prow-shaped.

mostly extravaginal, some intravaginal.

extravaginal.

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.

14-30 cm, open, sparse, with 1-3(4) branches per node;

branches (5.5)8-12(15) cm, widely spreading, fairly straight, angled, angles sparsely to moderately scabrous, with 3-13 spikelets.

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.

4-8 mm, laterally compressed, rarely bulbiferous;

florets 2-4, usually normal, rarely bulb-forming;

rachilla internodes about 1 mm, smooth, glabrous.

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.

distinctly keeled, keels scabrous;

lower glumes lanceolate, 1-3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas 3.2-6 mm, lanceolate, distinctly keeled, smooth or sparsely finely scabrous, keels and marginal veins long-villous, keels hairy to 2/3 – 3/4 their length, marginal veins sparsely hairy, lateral veins moderately prominent, usually glabrous, rarely sparsely softly puberulent, intercostal regions glabrous, apices acute;

paleas scabrous, glabrous over the keels;

anthers 0.5-1.1 mm.

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

= ca. 98.