Flora of North America species comparison

20-110 cm, erect;

nodes glabrous.

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

glabrous or pubescent;

ligules 0.2-0.5 mm;

blades 5-31 cm long, 2-10 mm wide, flat or conduplicate, glabrous or pubescent.

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, usually composed of a digitate pair of branches, 1-3 additional branches sometimes present below the terminal pair;

branches 3-15 cm, diverging to erect;

branch axes 0.7-1.8 mm wide, narrowly winged, glabrous, margins scabrous, terminating in a spikelet, distal spikelets sometimes reduced.

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.

2.5-4 mm long, 2-2.8 mm wide, solitary, appressed to the branch axes, broadly elliptic to ovate or obovate, glabrous, light stramineous to white, apices obtuse to broadly acute.

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.

2-3 mm, white.

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).

glumes absent;

upper glumes glabrous, 5-veined;

lower lemmas 5-veined, margins inrolled;

upper florets light yellow to white.

= 20, 30, 40.