Flora of North America species comparison

30-75 cm, erect.

15-95 cm, erect or decumbent and rooting at the lower nodes.

glabrous;

ligules about 0.5 mm, shortly ciliate;

blades to 20 cm long, to 5 mm wide, sometimes with long basal hairs, otherwise scabrous.

glabrous;

ligules 0.3-0.5 mm, erose to lacerate;

blades to 15 cm long, 0.3-0.6 mm wide, with basal hairs, otherwise usually glabrous.

with 5-17, evidently distinct branches in 1-3 closely-spaced whorls;

branches to 7 cm, usually erect when young, spreading to reflexed at maturity, averaging 12 spikelets per cm.

digitate, with 7-15 evidently distinct branches;

branches 3-8 cm, more or less erect, averaging 14 spikelets per cm.

with 1 bisexual and 1 staminate floret.

with 1 bisexual and 2(3) sterile florets.

1.5-3.2 mm;

upper glumes 2.5-3.4 mm;

lowest lemmas 2.8-3.7 mm long, 0.6-1.1 mm wide, broadly linear to elliptic, mostly glabrous but the margins appressed pubescent, apices obtuse, not conspicuously bilobed, sometimes shortly mucronate;

second florets 1.4-2.2 mm long, 0.3-0.9 mm wide, usually at least twice as long as wide, not lobed, unawned, occasionally mucronate.

1.2-2.1 mm;

upper glumes 2.3-2.7 mm;

lowest lemmas 2-2.7 mm, ovate to elliptic, calluses and distal portion of the margins pilose, hairs to 1 mm, keels glabrous or pilose, apices awned, awns 4-7.7 mm;

second florets 0.9-1.3 mm long, 0.4-0.9 mm wide, slightly to strongly widened distally, inflated, usually glabrous, truncate, awned, awns 5-7 mm;

third florets obovoid to subspherical, smaller than the first, strongly inflated.

1.7-2.3 mm long, 0.5-0.6 mm wide, ellipsoid.

1.1-1.4 mm.

= ca. 65, 80.

= 20, 40, ca. 50.