Flora of North America species comparison

40-80 cm, disarticulating at the nodes when mature.

7-130 cm, erect.

glabrous, rarely sparsely pilose, usually reddish above the nodes;

blades to 30 cm long, 2-4 mm wide, flexible but not curled at maturity, glabrous, sometimes scabrous, uppermost cauline blades erect to ascending.

open to the base, with tufts of hairs at the auricle position, sometimes with a line of hairs around the collar;

auricles absent;

ligules of hairs;

blades rolled in the bud, flat or involute when dry.

with (4)6-17 spikelets;

branches usually flexible, usually divergent, sometimes strongly so, after anthesis;

lower branches with 2-3 spikelets;

pedicels on the lowest branch as long as or longer than the spikelets.

terminal;

panicles, racemes, or a solitary spikelet, to 12 cm;

rachises, branches, and pedicels scabrous or hirsute.

(7)10-16 mm.

terete or laterally compressed, with 3-12 florets, terminal floret reduced;

disarticulation beneath the florets, also at the cauline nodes in some species.

subequal or the lower glumes a little longer than the upper glumes, usually exceeding the florets (excluding the awns and lemma teeth), lanceolate, chartaceous, 1-7-veined, keels glabrous or sparsely scabrous;

rachillas glabrous;

calluses densely strigose on the sides;

lemma bodies obscurely (5)7-11-veined, backs glabrous or pilose, margins usually densely pilose proximally, apices with 2 acute to aristate lobes, mucronate or awned between the lobes;

awns, when present, geniculate and twisted below the geniculation;

paleas about as long as the lemma bodies, 2-veined, veins scabrous, apices obtuse, sometimes bifid;

lodicules 2, glabrous or with a few hairs;

anthers 3, their size depending on whether the florets are chasmogamous or cleistogamous;

ovaries glabrous.

1.7-2.6 mm long, 0.7-1.1 mm wide.

1.5-5.5 mm, ovate to obovate, dorsally flattened, brown;

hila linear, 1/3 – 3/4 as long as the caryopses.

of middle florets about as long as wide, convex abaxially;

lemma bodies 2.5-5 mm, pilose over the back, sometimes sparsely so, margins pilose to beyond midlength, distal hairs 0.5-2 mm, apical teeth 2-4 mm, aristate, (1/2)2/3 or more as long as the lemma bodies;

awns 6-10 mm;

anthers to 2.2 mm.

usually present in the lower sheaths, with 1(-10) florets, not disarticulating;

rachilla segments about as long as or longer than the adjacent florets;

lemmas coriaceous, glabrous or scabrous near the apex, entire, unawned;

paleas sometimes slightly longer than the lemmas;

anthers 3, minute;

ovaries glabrous;

caryopses more linear than in the aerial florets, x = 12.

= 36.