Flora of North America species comparison

15-35 cm, stiffly erect, all but the upper 2-4 internodes very short;

nodes glabrous or with weak, reflexed hairs;

internodes purplish-gray, sparsely pubescent;

fall phase developing early, forming erect branches from the lower or midculm nodes, each branch terminating in a partially included panicle of 8-16 spikelets, no sterile shoots formed.

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.

usually 3;

sheaths hirsute, hairs papillose-based;

ligules 0.5-1 mm;

blades 4-8 cm long, 2-5 mm wide, all alike, stiffly erect, green to grayish-green, flat, not plicate, sparsely pilose.

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.

2.4-3.2 mm long, 0.7-1.2 mm wide, ellipsoid to obovoid, often reddish throughout, short-pubescent.

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.

0.7-1.2 mm, triangular;

upper glumes and lower lemmas about equaling the upper florets;

upper florets 1.9-2.5 mm, ellipsoid, pointed.

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).

rosettes poorly differentiated;

sheaths glabrous;

blades 2-4 cm, narrow, similar to those of the lower cauline leaves, ascending to spreading.

panicles 3-5 cm long, 2-4 cm wide, ovoid, open, shortly exserted, with 12-32 spikelets;

branches short, stiff, spreading;

pedicels mostly 4-8 mm, spreading.

= 18.