Flora of North America species comparison

annual or perennial, not woody, branches 1 to many at the upper nodes.

often persistent, sometimes geniculate at the base, sometimes with stiff branches at the upper nodes;

basal branching usually extravaginal;

prophylls not evident.

basally concentrated to evenly distributed;

sheaths open, margins not fused, sometimes ciliate distally, basal sheaths sometimes concealing axillary panicles (cleistogenes), sometimes wider than the blade;

collars sometimes with tufts of hair at the sides extending to the top of the sheaths;

auricles absent;

ligules scarious, often ciliate, cilia usually shorter than the base, ligules of the lower and upper cauline leaves sometimes differing in size and vestiture;

pseudopetioles absent;

blades linear to narrowly lanceolate, venation parallel, cross venation not evident, cross sections non-Kranz, without arm or fusoid cells;

epidermes of adaxial surfaces sometimes with unicellular microhairs, cells not papillate.

not overwintering;

sheaths open to the base, margins sometimes extending beyond the base of the ligule, the extensions often conspicuously hairy, sometimes grading into the ligule;

auricles not present;

ligules membranous;

blades flat, convolute, or terete, usually scabrous, sometimes pubescent, those of the flag leaves longer than 10 mm, bases usually as wide as the top of the sheaths, sometimes narrower.

usually terminal panicles, occasionally reduced to racemes in depauperate plants, sometimes 2-3 panicles developing from the highest cauline node.

panicles, sometimes contracted, rachises persistent or disarticulating whole at maturity;

pedicels smooth or scabrous, sometimes hairy, hairs to 3 mm;

disarticulation above the glumes, sometimes also at the base of the panicle.

usually with 1 floret, sometimes with 2-6 florets, laterally compressed to terete;

rachillas not prolonged beyond the base of the floret in spikelets with 1 floret, prolonged beyond the base of the distal floret in spikelets with 2-6 florets, prolongation hairy, hairs 2-3 mm;

disarticulation above the glumes and beneath the florets.

with 1 floret;

rachillas not prolonged.

usually exceeding the floret(s), always longer than 1/4 the length of the adjacent floret, 1-10-veined, narrowly lanceolate to ovate, hyaline or membranous, flexible;

florets usually terete, sometimes laterally or dorsally compressed;

calluses usually well-developed, rounded or blunt to sharply pointed, often antrorsely strigose;

lemmas lanceolate, rectangular, or ovate, membranous to coriaceous or indurate, 3-5-veined, veins inconspicuous, apices entire, bilobed, or bifid, awned, lemma-awn junction usually conspicuous, awns 0.3-30 cm, not branched, usually terminal and centric or eccentric, sometimes subterminal, caducous to persistent, not or once- to twice-geniculate, if geniculate, proximal segment(s) twisted, distal segment straight, flexuous, or curled, not or scarcely twisted;

lodicules 2 or 3;

anthers 1 or 3, sometimes differing in length within a floret;

ovaries glabrous throughout or pubescent distally;

styles 2(3-4)-branched.

usually longer than the florets, narrow, more or less keeled, hyaline to chartaceous, 1-5(7)-veined, apices usually acute or acuminate, rarely muticous or mucronate, remaining open after the floret falls;

florets at least 5 times longer than wide;

calluses strigose, usually sharp;

lemmas usually coriaceous or indurate, 3-5(7)-veined, margins thin, usually convolute, rarely involute, apices glabrous or pilose, with 0-2 minute to small, membranous lobes, awned, lemma-awn junction evident;

awns once- or twice-geniculate;

paleas from shorter than to subequal to the lemmas, flat between the veins, 0-2-veined;

lodicules 3 or 2;

anthers 3, frequently penicillate;

ovaries glabrous.

ovoid to fusiform, not beaked, pericarp thin;

hila linear;

embryos less than 1/3 the length of the caryopses.

fusiform, terete;

hila linear, nearly as long as the caryopses.

= 7, 8, 10, 11, 12.

= unknown.