Flora of North America species comparison

20-60 cm tall, about 1 mm thick, erect, internodes glabrous;

nodes 2-4, pubescent.

10-175(210) cm, sometimes branched at the upper nodes, branches flexible;

prophylls not evident, shorter than the sheaths.

glabrous, smooth;

collars glabrous, without tufts of hair at the sides;

ligules 0.5-2.5 mm, glabrous, obtuse;

blades 15-45 cm long, 0.2-0.6 mm wide, convolute, stiff, scabridulous.

mostly basal, not overwintering;

sheaths open;

cleistogenes sometimes present;

auricles absent;

ligules membranous, sometimes pubescent or ciliate;

blades of basal leaves 3-60 cm long, 0.2-8 mm wide, apices narrowly acute to acute, not sharp, flag leaf blades 1-80 mm, bases about as wide as the top of the sheaths.

8-25 cm, open, lax, sparse;

branches 2-6 cm, with 1-8 spikelets;

pedicels 3-12 mm.

terminal panicles, sometimes partially included at maturity.

3-22 mm, with 1 floret;

rachillas not prolonged beyond the base of the floret;

disarticulation above the glumes, beneath the floret.

subequal, 4-10 mm long, 0.9-1.2 mm wide, narrowly lanceolate, scabridulous, apices aristate;

florets 1.5-2.5 mm long, 0.7-0.9 mm wide, terete, widest near the top;

calluses 0.1-0.3 mm, acute, strigose, hairs reaching to midlength on the lemmas;

lemmas strongly tuberculate, particularly distally, mostly glabrous, narrowing abruptly to the crown, midveins pubescent proximally;

crowns about 0.5 mm long, about 0.2 mm wide, straight-sided, rims entire or irregularly lacerate, glabrous;

awns 15-35 mm, eccentric, straight to twice-geniculate;

anthers 3, 1-1.5 mm.

longer than the floret, narrowly lanceolate or ovate, basal portion usually purplish at anthesis, color fading with age, (1)3-5-veined, sometimes awned;

florets usually terete, sometimes slightly laterally compressed;

calluses blunt or sharp, glabrous or antrorsely strigose;

lemmas usually papillose or tuberculate, at least distally, sometimes smooth throughout, glabrous or variously hairy, strongly convolute, wrapping 1.2-1.5 times around the caryopses, apices not lobed, fused distally into crowns, these often evident by their pale color and constricted bases;

crowns mostly glabrous, rims often bearing hairs with bulbous bases;

awns terminal, centric or eccentric, deciduous or persistent, usually twice-geniculate, second geniculation often obscure;

paleas up to 1/2 as long as the lemmas, glabrous, without veins, flat;

lodicules 2 or 3, if 3, the third somewhat shorter than the other 2;

anthers 1 or 3, if 3, often of 2 lengths, penicillate;

ovaries glabrous;

styles 2, bases free.

about 1.2 mm, oblong, dark brown.

glabrous, not ribbed;

hila elongate;

embryos to 2/5 as long as the caryopses.

= 7, 8.

= 36.