Flora of North America species comparison

(10)35-90(120) cm, usually unbranched, smooth to slightly scabrous;

nodes 1-3(4).

usually hollow, sometimes solid.

usually smooth;

collars usually smooth, sometimes scabrous, rarely pubescent;

ligules (0.5)1-5.5(6) mm, truncate to obtuse, usually entire, sometimes lacerate;

blades (5)11-25(34) cm long, (1)1.5-5(6) mm wide, flat or involute, usually scabrous, rarely smooth, sometimes puberulent.

distichous;

sheaths usually open to the base, varying to closed for nearly their full length;

auricles present or absent;

abaxial ligules absent;

adaxial ligules scarious or membranous, sometimes puberulent or scabridulous, usually not ciliate, cilia sometimes shorter than the base;

pseudopetioles rarely present;

blades usually linear, sometimes broadly so, venation parallel;

cross sections non-Kranz, mesophyll nonradiate, adaxial palisade layer absent, fusoid and arm cells usually absent;

midribs usually simple;

adaxial bulliform cells present;

stomates with parallel-sided subsidiary cells;

epidermes usually lacking bicellular microhairs, sometimes with unicellular microhairs, papillae usually absent, when present, rarely more than 1 per cell.

(2)4-18(29) cm long, (0.7)1-2(2.8) cm wide, erect, contracted, sometimes interrupted, pale green to purple;

branches 1.4-5(9.5) mm, smooth or scabrous, usually spikelet-bearing to or near the base, sometimes only to midlength.

usually terminal, panicles, spikes, or racemes, usually ebracteate;

disarticulation usually below the florets, sometimes below the glumes, at the rachis nodes, or at the inflorescence bases.

2-4(5) mm;

rachilla prolongations 0.5-1.5 mm, hairs 1.5-3 mm.

usually bisexual, infrequently unisexual or mixed, usually laterally compressed or not compressed, occasionally dorsally compressed, with 1-30 sexual florets, distal floret(s) often reduced, infrequently spikelets with 1-2 reduced or staminate basal florets and a single terminal sexual floret.

usually less than 3 times as long as wide, rounded or keeled, usually smooth, rarely scabrous, keels smooth or scabrous, veins prominent to obscure, apices acute;

callus hairs (1)1.5-3(4.5) mm, (0.5)0.7-0.9(1.3) times as long as the lemmas, abundant;

lemmas 2-4(5) mm, 0.1-1.5 mm shorter than the glumes;

awns 1.5-2.5 mm, usually attached to the lower 1/10-1/2 of the lemmas, rarely beyond the midpoint, equaling or exserted slightly beyond the margins of the glumes, usually stout, rarely slender, usually distinguishable from the callus hairs, straight or bent;

anthers (0.9)1.2-1.8(2.4) mm, often sterile.

usually 2, upper or lower glumes sometimes absent, rarely both glumes absent;

lemmas without uncinate hairs, awned or not, awns single, basal to apical;

paleas usually well-developed, sometimes reduced or absent;

lodicules 2(3), usually lanceolate and broadly membranous distally, rarely truncate and fleshy, usually not veined or obscurely veined, sometimes distinctly veined, sometimes ciliate;

anthers (1, 2)3;

ovaries glabrous or sometimes hairy distally, sometimes with an apical appendage;

haustorial synergids absent;

styles (1)2 (-4), bases close together, sometimes fused.

hila linear, elliptic, ovate, or punctate;

endosperm usually hard, sometimes soft or liquid, with or without lipids, starch grains compound or simple;

embryos less than 1/2 the length of the caryopses;

epiblasts usually present;

scutellar cleft usually absent;

mesocotyl internode usually absent;

embryonic leaf margins overlapping, x = 7, 10.