Flora of North America species comparison

15-60 cm, erect.

30-60 cm, erect or decumbent, occasionally rooting at the lower nodes.

glabrous;

ligules 0.7-1 mm;

blades to 20 cm long, 2-4 mm wide, without basal hairs, glabrous or scabrous, upper cauline leaves often greatly reduced.

usually glabrous, occasionally pilose;

ligules membranous, shortly ciliate;

blades 10-30 cm long, to 10 mm wide, sometimes with long basal hairs, usually pilose elsewhere, occasionally glabrous or scabrous.

with 10-20 branches in several closely-spaced whorls;

branches 2-5 cm, spreading, with 14-18 spikelets per cm;

disarticulation beneath the glumes.

with 5-15, evidently distinct branches in 1-2(3) whorls;

branches 4.5-8 cm, spikelet-bearing to the base, with 11-15 spikelets per cm distally.

with 1 bisexual and 1 sterile floret.

with 1 bisexual and 1 sterile floret.

0.5-0.7 mm;

upper glumes 1-1.5 mm;

lowest lemmas 1.5-2 mm long, 0.7-1 mm wide, broadly elliptic, mostly glabrous but the keels and marginal veins appressed-pilose, obtuse, awned, awns 0.3-1.5 mm;

second florets 1-1.5 mm long and about equally wide, conspicuously inflated, spherical, with the distal portion of the margins inrolled, not or inconspicuously bilobed, lobes less than 1/5 as long as the lemmas, midveins sometimes excurrent to 1.5 mm.

0.7-1.6 mm;

upper glumes 2-2.7 mm;

lowest lemmas 2.8-3.3 mm long, 0.4-0.6 mm wide, lanceolate to elliptic, sides not conspicuously grooved, mostly glabrous, margins shortly ciliate distally, hairs less than 1 mm, apices awned, awns 6-13 mm;

second florets 0.4-0.7 long, about 0.1 mm wide, borne on an equally long or longer rachilla segment, not or inconspicuously bilobed, awned, awns 3-5 mm.

0.9-1.2 mm long, about 0.5 mm wide, obovoid.

1.4-1.5 mm long, 0.3-0.4 mm wide, ellipsoidal.

= 40.

= 40.