Flora of North America species comparison

15-45(65) cm, erect or decumbent, sometimes with crateriform glands below the nodes.

2-160 cm, not woody, erect, decumbent, or geniculate, sometimes rooting at the lower nodes, simple or branched;

internodes solid or hollow.

glabrous, occasionally glandular, apices hairy, hairs to 5 mm;

ligules 0.4-0.8 mm, ciliate;

blades (1)5-20 cm long, (1)3-5(10) mm wide, flat to involute, abaxial surfaces glabrous, sometimes glandular, adaxial surfaces scabridulous, occasionally also hairy.

not strongly distichous;

sheaths open, often with tufts of hairs at the apices, hairs 0.3-8 mm;

ligules usually membranous and ciliolate or ciliate, cilia sometimes longer than the membranous base, occasionally of hairs or membranous and non-ciliate;

blades flat, folded, or involute.

(3)5-16(20) cm long, 2-8.5 cm wide, oblong to ovate, condensed to open;

primary branches 0.4-5 cm, appressed or diverging 20-80° from the rachises;

pulvini glabrous or hairy;

pedicels 0.2-3 mm, stout, straight, stiff, usually divergent, occasionally appressed.

terminal, sometimes also axillary, simple panicles, open to contracted or spikelike, terminal panicles usually exceeding the upper leaves;

pulvini in the axils of the primary branches glabrous or not;

branches not spikelike, not disarticulating.

6-20 mm long, 2-4 mm wide, ovate-lanceolate, plumbeous, greenish, with 10-40 florets;

disarticulation below the florets, each floret falling as a unit, rachillas persistent.

1-27 mm long, 0.5-9 mm wide, laterally compressed, with (1)2-60 florets;

disarticulation below the fertile florets, sometimes also below the glumes, acropetal with deciduous glumes and lemmas but persistent paleas, or basipetal with the glumes often persistent and the florets usually falling intact.

broadly ovate to lanceolate, membranous, usually glandular;

lower glumes 1.2-2 mm, usually 1-veined;

upper glumes 1.2-2.6 mm, often 3-veined;

lemmas 2-2.8 mm, broadly ovate, membranous, keels with 1-3 crateriform glands, apices obtuse to acute;

paleas 1.2-2.1 mm, hyaline, keels scabrous, sometimes also ciliate, cilia to 0.3 mm, apices obtuse to acute;

anthers 3, 0.2-0.5 mm, yellow.

usually shorter than the adjacent lemmas, 1(3)-veined, not lobed, apices obtuse to acute, unawned;

calluses glabrous or sparsely pubescent;

lemmas usually glabrous, obtuse to acute, (1)3(5)-veined, usually keeled, unawned or mucronate;

paleas shorter than the lemmas, longitudinally bowed-out by the caryopses, 2-keeled, keels usually ciliate, intercostal region membranous or hyaline;

anthers 2-3;

ovaries glabrous;

styles free to the bases.

0.5-0.7 mm, globose to broadly ellipsoid, smooth to faintly striate, not grooved, reddish-brown or translucent.

variously shaped, x = 10.

spikelets occasionally present, sometimes on the axillary panicles, sometimes on the terminal panicles.

= 20.