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.

(4)9-250 cm, sometimes forming a basal corm;

nodes and internodes usually glabrous.

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.

closed almost to the top;

auricles sometimes present;

ligules thinly membranous, erose to lacerate, usually glabrous, those of the lower leaves shorter than those of the upper leaves;

blades flat or folded, glabrous or hairy, particularly on the adaxial surfaces, sometimes scabrous.

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.

terminal panicles;

primary branches often appressed;

secondary branches appressed or divergent;

pedicels either more or less straight or sharply bent below the spikelets, scabrous to strigose distally;

disarticulation below the glumes in species with sharply bent pedicels, above the glumes in other species.

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.

with 1-7 bisexual florets, terminating in a sterile structure, the rudiment, composed of 1-4 sterile florets;

rudiments sometimes morphologically distinct from the bisexual florets, sometimes similar but smaller.

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.

membranous or chartaceous, distal margins wide, translucent;

lower glumes 1-9-veined;

upper glumes 1-11-veined;

calluses glabrous;

lemmas membranous basally, sometimes becoming coriaceous at maturity, glabrous or with hairs, (4)5-15-veined, usually unawned, sometimes awned, awns to 12 mm, straight;

paleas from 1/2 as long as to almost equaling the lemmas, keels usually ciliate;

lodicules fused into a single, collarlike structure extending 1/2 - 2/3 around the base of the ovaries;

anthers (2)3.

usually 2-3 mm, smooth, glabrous, longitudinally furrowed, falling from the floret when mature, x = 9.

= 18.