317 
3. Empty glumes two : perfect flowers two in 
each spikelet 
3. Empty glumes three ; perfect flower one in 
each spikelet. 
4. Glumes unawned ; spikelets panicled 
or spicate 
4. Glumes unawned ; spikelets of Fani- 
cmii, but the flowering glume nar- 
rowed into a short stipe or with two 
appendages or pits at the base 
4. Empty glumes or flowering glumes 
awned or awn-pointed. 
5. Flowering glumes unawned ; 
empty glumes awned or awn- 
pointed. 
6. Prostrate or ascending, 
grasses ; racemes or 
clusters of few spike- 
lets ; empty glumes 
glabrous or pubescent.. 
6. Erect grasses ; racemes 
of many spikelets ; 
empty glumes often 
muricate-hispid 
5. Flowering glume awned ; nerves 
of the second empty glume 
broadly fimbriate ; palea of 
the third glume deeply cleft.. 
2. Spikelets subtended by an involucre, consisting of 
from one to many bristles . or spines which are 
sometimes grown together. 
3. Involucre of two spine-bearing valves 
3. Involucre of numerous bristles. 
4. Spikelets fasciculate ; involucral bris- 
tles falling with the spikelet 
4. Spikelets usually solitary ; involucral 
bristles persistent after the fall of 
the spikelet 
3. Involucre of solitary bristles. 
4. Inflorescence in open panicles ; pros- 
trate aquatic grasses 
4. Inflorescence in dense cylindrical 
spikes or spike-like panicles ; erect 
grasses 
1. Spikelets monoecious or dioecious. 
2. Monoecious ; slender prostrate grasses ; inflores- 
cence a terminal spike, the two lower spikelets 
perfect, the four to six upper ones staminate.. 
2. Dioecious ; very coarse prostrate grasses ; pistillate 
flowers collected into large globose heads with 
very long spines ; staminate flowers in umbel- 
lately disposed racemes 
(28) Isachiie 
(29) Pariiciim 
(30) Ichnanthus 
(31) Oplismcnus 
(29) Panicum § Echinochloa 
(33) Axnnopus 
( 34 ) Ceiichriis 
(35) Pennisetuin 
( 32 ) Setaria 
(35) Chcunaeraphis 
(32) Setaria 
(37) Tluiarea 
(38) Spin if ex 
Tribe VI. OKYZE^. 
1. Spikelets unisexual ; fruiting glumes inflated : leaves broad.. (39) Leptaspis 
1. Spikelets perfect ; fruiting glumes not inflated. 
2. Empty glumes two, short but distinct ; spikelets 
awned or awnless (40) Oryza 
2. Empty glumes wanting; spikelets awnless (il) Leersia 
Tribe VII. PHALARIBE^. 
1. First and second glumes minute, the third and fourth longer 
than the flowering glume : (42) Microlaena 
1 . First and second empty glumes equaling or exceeding the 
third and fourth (43) Anthoxanthum 
