Flora of North America species comparison

10-100+ cm.

to 135 cm.

usually glabrous;

ligules to 4 mm, erose or ciliate;

blades to 30 cm long, to 15 mm wide, basal hairs to 4 mm, otherwise usually glabrous, occasionally pilose.

mostly glabrous;

ligules 0.7-1 mm, erose to lacerate;

blades to 45 cm long, to 15 mm wide, with basal hairs, otherwise usually glabrous, occasionally scabrous.

digitate, with 4-20, evidently distinct branches;

branches 5-10 cm, erect to ascending, averaging 10 spikelets per cm.

digitate, with (4)8-28 evidently distinct and easily separable branches;

branches (5)8-20 cm, flexible, usually more or less spreading, sometimes drooping, averaging 12 spikelets per cm.

strongly imbricate, with 1 bisexual and 1(2) sterile floret(s).

strongly imbricate, with 1 bisexual and usually 2 sterile florets.

1.5-2.5 mm;

upper glumes 2.5-4.3 mm;

lowest lemmas 2.5-4.2 mm, keels usually prominently gibbous, glabrous, or conspicuously pilose, sides not grooved, margins glabrous, scabrous or pilose basally, with conspicuously longer hairs distally, hairs longer than 1.5 mm, lemma apices not conspicuously bilobed, awned, awns 2.5-15 mm;

second florets 1.4-2.9 mm long, 0.4-0.8 mm wide, somewhat widened distally, not inflated, bilobed, lobes less than 1/5 as long as the lemmas, awned from the sinuses, awns 3-9.5 mm;

third florets greatly reduced, unawned and shorter than the subtending rachilla segment or absent but the rachilla segment present.

1-2.5 mm;

upper glumes 1.9-3.5 mm;

lowest lemmas 1.5-2.8 mm long, 0.5-0.9 mm wide, elliptic, strongly laterally compressed, margins conspicuously hairy for most of their length, hairs 1-3 mm, strongly divergent, keels densely appressed pubescent, not or only minutely bilobed, apices awned, awns 1.4-4.8 mm;

second florets 1-1.6 mm, cylindrical to narrowly turbinate, shortly bilobed, lobes less than 1/5 as long as the lemmas, awned from the sinuses, awns 1.7-4 mm;

third florets often enclosed by the first sterile florets, 0.5-0.9 mm, turbinate or flabellate, as long as or longer than the subtending rachilla segments, sometimes inflated apically, unawned.

1.5-2 mm long, about 0.5 mm wide, elliptic.

about 1 mm long, about 0.5 mm wide.

= 20, 26, 30, 40.

= 72.