Flora of North America species comparison

15-60 cm, erect or spreading, bases bulbous.

20-110 cm.

closed for about 1/4 their length, terete, lowest sheaths with swollen bases;

ligules 1-3 mm, smooth or scabrous, apices obtuse to acute;

blades 1-2.5 mm wide, flat, thin, lax, soon withering.

closed for (1/5)1/4 – 1/2(3/5) their length, distinctly compressed and keeled, usually densely retrorsely scabrous, rarely sparsely scabrous, margins not ciliate;

ligules 3-12 mm, densely scabrous, acute to acuminate;

blades (1.2)1.5-6(10) mm wide, flat, lax, apices broadly prow-shaped.

intravaginal.

mixed intra- and extra-vaginal.

3-12 cm, ovoid;

nodes with 2-5 branches;

branches ascending to spreading, terete, usually smooth or sparsely scabrous, infrequently moderately scabrous.

(6)12-40 cm, lax, eventually open, spikelets numerous, with 2-7 branches per node;

branches (3)5-18(23) cm, eventually spreading or drooping, angled, angles densely scabrous, with (5)8-40(120) spikelets.

3-5 mm, laterally compressed, usually bulbiferous;

florets 3-7, the basal floret, and sometimes additional florets, normal;

rachilla internodes smooth, glabrous.

(3)4-7(8) mm, laterally compressed, with 3-7 florets;

rachilla internodes shorter than 1 mm, smooth.

keeled, keels scabrous;

lower glumes 3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed or glabrous;

lemmas 3-4 mm, lanceolate, keeled, glabrous or the keels and marginal veins short- to long-villous, intercostal regions glabrous or softly puberulent, apices acute;

paleas scabrous, keels often softly puberulent at midlength;

anthers 1.2-1.5 mm and functional, sometimes aborted late in development, sometimes not developed.

distinctly keeled, keels scabrous;

lower glumes 2-3.5 mm, 1-veined;

upper glumes 2.5-4.2 mm, shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas 2.6-4.2 mm, narrowly lanceolate, distinctly keeled, scabrous distally, keels and marginal veins short- to long-villous, keel hairs extending to midlength, marginal vein hairs to 1/3 the lemma length, lateral veins and intercostal regions usually sparsely softly puberulent, lateral veins prominent, apices narrowly acute;

palea keels scabrous, glabrous;

anthers 0.3-1 mm.

= 14, 21, 28, 39, 42, 45.

= 14, 28.