154 



Racemes in large much branched silky panicles, rhachis 



fragile. Spikelets awned. 

 Racemes 2-nate, digitate or approximate on a short 



axis. 



B. 



Sessile spikelets not sunk in hollows. Racemes spiciform, 

 solitary 2-nate, digitate or approximate on a 

 short main axis. Lower floret of the sessile 

 spikelet always male. 



Sessile spikelets sunk in hollows formed by the con- 

 tiguous joint of the rhachis and the aj^tpressed 

 or adnate pedicel of the 2:)edicelled spikelet of 

 the same pair. 



Rhacbis as in Saccharum and Ischseum. Racemes 

 variously arranged. Lower floret of all spikelets 

 empty ; upper floret usually awned. 

 1 All spikelets awnless. 



1 Pedicelled spikelets long awned. 



2 Rhachis tough, indistinctly articulate. Spikelets 

 all pedicelled, the fruiting one deciduous. 



2 Rhachis of the spike-like solitary raceme fragile, 

 one spikelet of eacli pair sessile, the other 

 pedicelled, both awnless. 



2 Racemes solitary, 2-nate, digitate or pedicelled ; 

 rhachis fragile. The sessile sj)ikelet awned, 

 but not from the upper valve. No whorl of 

 male spikelets at base of the raceme, or where 

 an imiDcrfect one occurs the racemes are always 

 paired, and each pair is subtended by a spathe. 



2 "Racemes short, crowded on spathaceous panicled 

 fascicles, each with a whorl of 4 or more male 

 or barren spikelets at the base, and supported 

 by a proper spathe. 



TRIBE IL PANICEJB. 



Glumes and low valve entire, awnless or caudate, or 

 subulate aristate. Fruiting valve sub-charta- 

 ceous to crustaceous. 



Glumes and lower valve 2-lobed or emarginate with 

 a fine awn or mucro from the sinus, rarely all 

 muticous. Fruiting valve rigidly membranous. 



1 Mature spikelets falling entire and singly from the 

 tips of their pedicels. 



1 Mature spikelets not falling singly or not from the 

 tips of their pedicels. 



2 Spikelets awnless. Lower glume 0. Lower 



valve quite empty, nerves 5 or fewer, side- 

 nerves curved, usually sub-marginal. 



Erianthus. 



POLLINIA. 



ISCH^MUM. 



rottb(ellia. 

 Urelytrum. 



Trachypoqon. 

 Elionurus. 



Andropogon. 



Anthistiria. 



Paspalum. 



