Flora of North America species comparison

(60)100-250 cm tall, about 10 mm thick, mostly erect, sometimes geniculate and rooting at the lower nodes;

nodes pubescent or glabrous.

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

usually shorter than the internodes, glabrous or pubescent, sometimes with papillose-based hairs, margins sometimes ciliate;

collars densely pubescent, hairs appressed or divergent;

ligules 1-3 mm;

blades (15)30-75(100) cm long, 10-35 mm wide, flat, erect or ascending, glabrous or pubescent, sometimes with appressed papillose-based hairs, margins scabrous, sometimes ciliate basally, midveins conspicuous, sunken, whitish.

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.

20-65 cm, about 1/3 as wide as long, open, rachises smooth or scabrous;

primary branches usually more than 20, 12-40 cm, axes 0.4-0.6 mm wide, not winged, ascending, those of the lower node(s) verticillate and pilose at the base, upper axils glabrous, lower branches naked basally;

secondary and tertiary branches well-developed;

pedicels 0.5-1.5 mm, unequal, straight or curved, glabrous or with a single setaceous hair near the apex.

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.

2.7-3.6 mm long, 0.9-1.1 mm wide, oblong-ellipsoid, usually glabrous (rarely densely covered with papillose-based hairs), solitary, paired (or in triplets), usually appressed to the branch axes.

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

scarcely separate, rachilla between the glumes not pronounced;

lower glumes 0.8-1.2 mm, 1-3-veined, obtuse or truncate, glabrous;

upper glumes 2.1-3.5 mm, 5-veined, glabrous;

lower lemmas 2.1-3.5 mm, subequal, glabrous, 5-veined, without cross venation, acute, muticous or mucronate;

lower florets staminate;

upper lemmas 1.9-2.4 mm, ellipsoid, pale, glabrous, apices acute, mucronulate;

anthers 1.2-2.2 mm.

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).

= 18, 32, 36, 44, 48.