Flora of North America species comparison

30-60 cm, bases orange-brown;

nodes 3-6;

basal branching intravaginal.

usually hollow, sometimes solid.

mostly glabrous, throats densely ciliate, basal sheaths reddish brown, flat and ribbonlike with age;

ligules varying within a plant, lower ligules 0.3-1 mm, densely hairy and ciliate, hairs 0.2-1 mm, often longer than the basal membrane, upper ligules to 2.5 mm, hyaline to scarious, glabrous or hairy, usually less hairy than the lower ligules, sometimes ciliate;

blades 10-30 cm long, 0.5-2 mm wide when flat, usually rolled, to 1 mm in diameter, abaxial surfaces glabrous, smooth, adaxial surfaces pilose.

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.

10-15 cm, dense, frequently partially included in the upper leaf sheaths at maturity;

branches ascending.

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.

16-24 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.

linear-lanceolate, glabrous, tapering from below midlength to the narrowly acute apices;

lower glumes 16-24 mm, 1-veined;

upper glumes 13-19 mm, 3-5-veined;

florets (6)8-10 mm;

calluses 0.8-1.6(3) mm, sharp;

lemmas densely and evenly hairy, hairs about 0.5 mm, without a pappus;

awns 35-45(80) mm, once-geniculate, first segment pilose, hairs 3-8 mm, terminal segment glabrous, smooth;

paleas 3.2-5.1 mm, 2/5 – 2/3 (4/5) the length of the lemmas, usually hairy, hairs about 0.5 mm.

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.

= 66, 68, about 74.