Flora of North America species comparison

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

5-15(20) cm, slender, leafless above the basal tuft.

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 1/10 – 1/4 their length, terete;

ligules 0.4-5.5 mm, milky white to hyaline, smooth or scabrous, apices truncate to acute;

blades 0.8-1.5(2) mm wide, involute, moderately thick, soft, apices narrowly prow-shaped.

mostly extravaginal, some intravaginal.

all or mainly intravaginal.

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.

1.5-5 cm, erect, lanceoloid to ovoid, contracted, congested;

nodes with 1-3 branches;

branches to 1.5 cm, erect, slender, terete, sulcate or angled, smooth or the angles sparsely scabrous;

pedicels usually shorter than the 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.

4-6.5 mm, laterally compressed, rarely bulbiferous, frequently strongly anthocyanic;

florets 2-5, rarely bulb-forming;

rachilla internodes usually shorter than 1 mm, smooth or scabrous.

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.

subequal to slightly longer than the adjacent lemmas, lanceolate to broadly lanceolate, distinctly keeled, keels smooth;

lower glumes (1)3-veined, lateral veins often faint and short;

upper glumes exceeding or exceeded by the upper florets;

calluses glabrous or webbed;

lemmas 3-4.6 mm, lanceolate to broadly lanceolate, distinctly keeled, thin, keels and marginal veins usually short- to long-villous, hairs extending along 3/4 - 5/6 of the keel, infrequently glabrous, intercostal regions glabrous or softly puberulent to short-villous, apices acute;

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

anthers 0.2-1.2(1.8) mm.

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

= 42.