Flora of North America species comparison

20-120 cm, erect to decumbent, often rooting at the lower nodes, branching above the bases.

annual, usually solid, sometimes somewhat woody, sometimes decumbent, often branched above the base.

not aromatic;

sheaths open;

auricles absent;

ligules membranous, ciliate.

distichous;

sheaths usually open;

auricles usually absent;

abaxial ligules usually absent, occasionally present as a line of hairs;

adaxial ligules membranous, sometimes also ciliate, or of hairs, sometimes absent;

blades sometimes pseudopetiolate;

mesophyll radiate or non-radiate;

adaxial palisade layer absent;

fusoid cells usually absent;

arm cells usually absent;

kranz anatomy absent or present;

midribs usually simple, rarely complex;

adaxial bulliform cells present;

stomata with triangular or dome-shaped subsidiary cells;

bicellular microhairs usually present, with a long, narrow distal cell;

papillae absent or present.

terminal and axillary, solitary, 2-sided rames, these sometimes fascicled and partially enclosed in subtending leaf sheaths at maturity;

disarticulation in the rames, beneath the sessile spikelets.

ebracteate (Paniceae) or bracteate (most Andropogoneae) panicles, racemes, spikes, or complex arrangements of rames (in the Andropogoneae), usually bisexual, sometimes unisexual;

disarticulation usually below the glumes, frequently in the secondary and higher order axes of the inflorescences.

in heterogamous sessile-pedicellate pairs.

bisexual or unisexual, frequently paired or in triplets, the members of each unit usually with pedicels of different lengths or 1 spikelet sessile.

usually 2, equal or unequal, shorter or longer than the adjacent florets, sometimes exceeding the distal florets;

florets 2(-4), usually dorsally compressed, sometimes terete or laterally compressed;

lower florets sterile or staminate, frequently reduced to a lemma;

upper florets usually bisexual;

lemmas hyaline to coriaceous, lacking uncinate hairs, often terminally awned;

awns single;

paleas of bisexual florets well-developed, reduced, or absent;

lodicules usually 2, sometimes absent, cuneate, free, fleshy, usually glabrous;

anthers 1-3;

ovaries usually glabrous;

haustorial synergids absent;

style branches 2, free and close or fused at the base.

hila usually punctate;

endosperm hard, without lipid;

starch grains simple;

embryos large in relation to the caryopses, usually waisted;

epiblasts usually absent;

scutellar cleft present;

mesocotyl internode elongated;

embryonic leaf margins usually overlapping, rarely just meeting, x = 5, (7), 9, 10, (12), (14).

adnate to the rame axes, concealed by the sessile spikelets.

spikelets hemispherical, partly embedded in the rame axes;

lower glumes as long as the spikelets, indurate, alveolate, indistinctly 7-11-veined, not keeled, margins involute;

upper glumes chartaceous, 3-veined, usually adherent to the rame axes;

lower florets sterile;

upper florets bisexual;

anthers 3.

spikelets as long as or longer than the sessile spikelets, ovate;

lower glumes dorsally compressed, 5-9-veined;

upper glumes laterally compressed, 5-7-veined;

lower florets sterile;

upper florets staminate;

anthers 3.

= 7 (probably).