Flora of North America species comparison

60-160 cm, thickened basally, sometimes appearing cormous;

internodes sometimes pubescent below the nodes.

55-100 cm, not forming corms;

internodes smooth, basal internodes not thickened.

usually glabrous, sometimes pilose or retrorsely scabrous, particularly at the throat, veins often prominent;

ligules 2-4 mm;

blades 15-25 cm long, 5-12 mm wide, both surfaces usually scabridulous, glabrous, sometimes the adaxial surfaces with hairs.

often scabrous on the keels, otherwise smooth;

ligules 1-7 mm;

blades 2-5 mm wide, both surfaces glabrous, scabridulous.

12-30 cm;

branches 7-11 cm, spreading to reflexed, with 4-7 spikelets, spikelets restricted to the distal portion, axils frequently with brownish pulvini;

pedicels straight;

disarticulation above the glumes.

13-25 cm;

branches 1-9 cm, straight and appressed or flexible and ascending to strongly divergent, with 1-12 spikelets;

pedicels sharply bent below the spikelets;

disarticulation below the glumes.

12-18 mm, with 3-5 bisexual florets;

rachilla internodes 2.5-3 mm.

8-16 mm long, 1.5-5 mm wide, parallel-sided when mature, with 2-5 bisexual florets;

rachilla internodes 1.9-2.1 mm.

green, pale, or purplish-tinged;

lower glumes 3.5-6 mm long, 2-3 mm wide, 3-5-veined;

upper glumes 5-8 mm long, 2-3 mm wide, 5-veined;

lemmas 6-10 mm, glabrous, chartaceous on the distal 1/3, 5-11-veined, veins conspicuous, apices rounded to acute, unawned;

paleas about 2/3 the length of the lemmas;

anthers 1-2.5 mm;

rudiments 1.8-5 mm, acute to acuminate, resembling the bisexual florets.

4.5-7 mm long, 1-1.5 mm wide, 1-3-veined;

upper glumes 6.5-9 mm long, 1.2-1.8 mm wide, 3-5-veined;

lemmas 9.5-12 mm, glabrous or scabrous, 7-veined, apices bifid to emarginate, awned, awns 3-10 mm;

paleas about 2/3 the length of the lemmas;

anthers 1.3-2.5 mm;

rudiments 3.5-6 mm, tapering, resembling the bisexual florets.

= unknown.

= 18.