Flora of North America species comparison

45-100 cm, forming corms, corms connected to the rhizomes by a rootlike, 10-30 mm structure, which usually remains attached to the corm;

internodes smooth.

usually hollow, sometimes solid.

usually glabrous, often pilose at the throat and collar;

ligules 0.1-2 mm;

blades 2-5 mm wide, abaxial surfaces scabridulous over the veins, adaxial surfaces usually glabrous.

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.

5-26 cm;

branches 2-5 cm, usually appressed, sometimes divergent and flexuous, with 2-3 spikelets;

pedicels not sharply bent;

disarticulation above the glumes.

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.

7-19 mm, with 3-7 bisexual florets, base of the distal florets concealed at anthesis;

rachilla internodes 1-2 mm, not swollen when fresh, not wrinkled when dry.

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 1/2 the length of the spikelets;

lower glumes 3.5-6.4 mm long, 1.5-3 mm wide, 1-3-veined;

upper glumes 5-7 mm long, 2.3-3.5 mm wide, 5-7-veined;

lemmas 6-9 mm, glabrous, scabridulous, 5-11-veined, veins inconspicuous, apices rounded to acute, unawned;

paleas about 73 the length of the lemmas;

anthers 1.5-3 mm;

rudiments 1.5-3.5 mm, acute, distinct from the bisexual florets, sometimes surrounded by a small sterile floret similar in shape to the bisexual florets.

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.

= 18.