Flora of North America species comparison

45-100 cm, forming corms, corms connected to the rhizomes by a rootlike, 10-30 mm structure, which usually remains attached to the corm;

internodes smooth.

60-200 cm, not forming corms, often branched from the lower nodes;

internodes smooth.

usually glabrous, often pilose at the throat and collar;

ligules 0.1-2 mm;

blades 2-5 mm wide, abaxial surfaces scabridulous over the veins, adaxial surfaces usually glabrous.

glabrous, sometimes scabridulous, sometimes purplish;

ligules 2.5-9 mm;

blades 2-5 mm wide, abaxial sufaces scabridulous, adaxial surfaces puberulent.

5-26 cm;

branches 2-5 cm, usually appressed, sometimes divergent and flexuous, with 2-3 spikelets;

pedicels not sharply bent;

disarticulation above the glumes.

12-40 cm;

branches 3.5-9 cm, appressed, with 5-15 spikelets;

pedicels straight;

disarticulation above the glumes.

7-19 mm, with 3-7 bisexual florets, base of the distal florets concealed at anthesis;

rachilla internodes 1-2 mm, not swollen when fresh, not wrinkled when dry.

9-18 mm, with 3-5 bisexual florets;

rachilla internodes 1-1.3 mm, not swollen when fresh, not wrinkled when dry.

usually less than 1/2 the length of the spikelets;

lower glumes 3.5-6.4 mm long, 1.5-3 mm wide, 1-3-veined;

upper glumes 5-7 mm long, 2.3-3.5 mm wide, 5-7-veined;

lemmas 6-9 mm, glabrous, scabridulous, 5-11-veined, veins inconspicuous, apices rounded to acute, unawned;

paleas about 73 the length of the lemmas;

anthers 1.5-3 mm;

rudiments 1.5-3.5 mm, acute, distinct from the bisexual florets, sometimes surrounded by a small sterile floret similar in shape to the bisexual florets.

7-12 mm long, 2-3 mm wide, 5-7-veined;

upper glumes 8-15 mm long, 2.5-3.5 mm wide, 5-7-veined;

lemmas 8-11 mm, glabrous, chartaceous for the distal 1/3 or more, 7-9-veined, sometimes purplish basally, veins inconspicuous, apices rounded to acute, unawned;

paleas about 3/4 the length of the lemmas;

anthers 3, 1-2 mm;

rudiments 2-6 mm, blunt, enclosed in empty lemmas resembling those of the bisexual florets.

= 18.

= 18.