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.

annual, not woody, not branching above the base;

internodes hollow.

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 for their whole length or almost so;

collars without tufts of hair on the sides;

auricles sometimes present;

ligules hyaline, glabrous, often lacerate, occasionally ciliate, those of the lower and upper cauline leaves usually similar;

pseudopetioles absent;

blades linear to narrowly lanceolate, venation parallel, cross venation sometimes evident;

cross sections non-Kranz, without arm or fusoid cells;

epidermes without microhairs, sometimes papillate.

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 or racemes;

disarticulation above the glumes and beneath the florets or below 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.

2.5-60 mm, not viviparous, slightly to strongly laterally compressed, with 1-30 florets, proximal florets bisexual, distal 1-3 florets usually sterile, sometimes pistillate, sometimes reduced and amalgamated into a knob- or club-shaped rudiment;

rachillas prolonged beyond the base of the distal floret.

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.

exceeded by the distal florets, shorter than to longer than the adjacent lemmas, mostly membranous, scarious distally, 1-11-veined, apices usually rounded to acute;

florets laterally or dorsally compressed;

calluses blunt, glabrous or with hairs;

lemmas of sexual florets rectangular or ovate, mostly membranous, scarious distally, often with a purplish band adjacent to the scarious apices, (4)5-15-veined, veins not converging distally, often prominent, unawned or awned, awns not branched, apices entire to bilobed or bifid, awns straight, subterminal or from the sinuses;

paleas from shorter than to longer than the lemmas, similar in texture, 2-veined, veins keeled, sometimes winged;

lodicules 2, fleshy, usually connate into a single structure, without a membranous wing, truncate, not ciliate, not or scarcely veined;

anthers 1, 2, or 3;

ovaries glabrous;

styles 2-branched, bases persistent, branches plumose distally.

ovoid to ellipsoid, longitudinally grooved or not;

hila usually linear;

embryos less than 1/3 as long as the caryopses.

= (8)9, 10.

= 18.