ANDROPOGONEA 165 
B. First glume flattened or somewhat convex. 
Florida POUR sey ip anne CaN? SNe AS OO MANISURIS. 
BB. First glume hard and globular, pitted. 
BOM LO? ATIZONS,. s/o seek obs Guanes RyYTILIx. 
AA. Axis of the spike or raceme hairy, not exca- 
vated nor greatly thickened; fertile lemma 
usually awned. 
B. Spikelets all alike. 
c. Axis of racemes continuous. 
D. Racemes in a narrow spike-like panicle; 
spikelets awnless. Florida........... IMPERATA. 
pp. Racemes in a broad fan-shaped panicle; 
solkelete-awmedlie: oe saa eee MIScANTHUS 
cc. Axis of racemes breaking up into joints; (Par. 204). 
racemes in a much-branched panicle on 
a main axis. 
Pe SUSIE Ta WHE... cua awe ao latins week ERIANTHUS 
(Par. 206). 
DH; Spikelets awnless. 0s. Fee knee SACCHARUM 
BB. Spikelets not all alike, one of the pair perfect, (Par. 205). 
the other staminate, neutral or reduced to 
a pedicel. 
C. Brule spikelet pedicelled, with a long 
plumose awn; sterile spikelet nearly 
sessile, anal. ee nee Toca. TRACHYPOGON. 
cc. Fertile spikelet sessile; sterile spikelet 
pedicelled; axis articulate. 
pD. Spikelets ‘awnless; raceme solitary, ter- 
minating the SS ER eM AN et ELIONURUS. 
DD. Spikelets awned; racemes 1 or more 
from each sheathing bract but not 
solitary on the culms; sometimes re- 
duced to the terminal joint of 3 spike- 
lets and borne in panicles. 
E. Sessile spikelets all alike in the same 
raceme. 
F. Racemes several-flowered......... ANDROPOGON 
FF. Racemes reduced to 1 or 2 joints, (Par. 208). 
these in panicles. 
G Awn several inches long........ CHRYSOPOGON. 
ac. Awn short. 
H. Plants perennial, without rhi- 
zomes; sterile spikelet re- 
duced to a pedicely....c.28 5 SORGHASTRUM. 
HH. Plants perennial, with rhi- 
zomes, or annual; sterile 
spikelets Stamina. 7025). 50 Hocus 
EE. Sessile spikelets at the base of the (Par. 210). 
spike different from the others. 
