Flora of North America species comparison

10-100+ cm.

30-50 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.

glabrous;

ligules short-ciliate;

blades 9-17 cm long, 0.2-0.3 mm wide, without basal hairs, glabrous, sometimes scabrous.

digitate, with 4-20, evidently distinct branches;

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

digitate, with 5-13 clearly distinct branches;

branches 5-23 cm, spikelet-bearing to the base or within 1 cm of the base, averaging 6 spikelets per cm elsewhere.

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

dark brown to black, with 1 bisexual and 1(2) staminate floret(s).

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.

1.4-2.3 mm;

upper glumes 2.8-4.2 mm;

lowest lemmas 1.8-4.5 mm long, 0.2-0.7 mm wide, narrowly elliptic, becoming very dark, often almost black at maturity, sides not grooved, mostly glabrous but the margins appressed pubescent, sometimes sparsely so, hairs shorter than 1 mm, apices truncate, awned, awns 3.1-16 mm;

second florets 1.3-3.5 mm long, 0.5-0.9 mm wide, not inflated, truncate, not or only minutely bilobed, awned, awns 3.1-12.5 mm;

anthers about 0.6 mm.

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

1.7-2.2 mm long, 0.3-0.5 mm wide, ellipsoid to narrowly obovate, trigonous.

= 20, 26, 30, 40.

= 40.