Flora of North America species comparison

1-2.5 m;

nodes sericeous, hairs to 5 mm.

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

glabrate or glabrous;

auricles absent;

ligules 2-6 mm;

blades usually 35-70 cm long, 8-30 mm wide, adaxial surfaces glabrous or pilose.

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.

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.

40-80 cm, pilose;

panicles 6-15 cm wide, oblong or lanceolate;

rachises 15-30 cm, pilose;

lowest nodes densely pilose;

primary branches 2-13 cm, ascending or appressed to the rachises;

rame internodes 2-5.5 mm, pilose.

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).

2.5-5 mm, pilose.

spikelets 4.2-6 mm long, 0.8-1.1 mm wide, straw-colored.

hairs (7)15-20(25) mm, longer than the spikelets, straw-colored or brown;

glumes usually glabrous;

lower glumes smooth, indistinctly 5-veined;

lower lemmas 3-5 mm, without veins;

upper lemmas 2.5-3.5 mm, 1-veined, entire;

awns 12-26 mm, straight or curved, terete basally;

lodicule veins sometimes extending into hairlike projections;

anthers 2.

spikelets similar to the sessile spikelets, except frequently pilose.

= 30, 60, 90.