Flora of North America species comparison

to 5 m long, long-decumbent and rooting at the lower nodes, vertical portion 90-200(300) cm;

nodes villous.

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

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.

10-25 cm long, 5-10 cm wide, pyramidal, with 10-30 spikelike branches in more than 2 ranks;

primary branches 2.5-8 cm long, 0.4-0.9 mm wide, ascending to divergent, axils pubescent, axes flat, glabrous or with a few papillose-based hairs, secondary branches present or absent;

pedicels shorter than the spikelets, scabrous, sometimes with hairs.

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.

2.6-3.5 mm long, 1-1.4 mm wide, mostly in pairs, in 2-4 rows, appressed to the branches, purplish to green.

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 internodes short not pronounced;

lower glumes 0.6-1.1 mm, 1/5 – 1/3 as long as the spikelets, glabrous, 0-1(3)-veined;

upper glumes 2.6-3.5 mm, glabrous, 5-(7)-veined, without cross venation;

lower florets staminate;

lower lemmas 2.6-3.3 mm, glabrous, 5-veined, without cross venation;

upper lemmas 2.3-2.8 mm long, 1-1.3 mm wide, apices rounded, mucronate;

anthers 1-1.5 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.

1.8-2 mm.

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).

sheaths with papillose-based hairs, these more dense distally, margins ciliate;

collars pubescent;

ligules 1-1.5 mm;

blades 7.5-35 cm long, 4-20 mm wide, glabrous or sparsely pilose on both surfaces, margins scabrous.

= 18, 36.