GENERA AND SPECIES. 
Flowering glume several-nerved ; awn terminal, between 
rigid lobes or lateral awns, rarely infra-terminal ; 
spikelets in panicles : a we oo 
Flowering glume 3-lobed, central one awned; spikelets 
sessile in 2 rows on one side of 1 or 2 simple spikes 
Glumes awned; spikelets sessile, alternate on the sides 
of a simple spike, their flat side turned to the 
rhachis + ser na oes hs f 
Glumes with long awn-like points; rhachis with long 
hairs enveloping the flowers; panicle large, dense 
Grain adnate to the palea, flowering glumes awned. 
Ovary pubescent; flowering glume with a hyaline 
tip, the awn attached below it; panicle small ... 
Ovary glabrous, flowering glume acute, awn ter- 
minal; panicle loose Bs 
b. Flowering glume only minutely pointed, 
Flowering glume with 2 hyaline lobes besides the ter- 
minal point; inflorescence spicate or in narrow 
panicles ... = Hit ie 
Flowering glume obtuse or notched, 5-nerved, the cen- 
tral nerve minutely pointed; panicle narrow, long 
c. Spikelets awnless, 
Spikelets arranged in spikes. 
Spikelets unisexual on separate plants 
Spikelets digatate at the end of the peduncles 
Spikelets in panicles. 
Flowering glume 3-lobed or 3-toothed; leaves pun- 
gent-pointed ... ae a aie A ee 
Flowering glume lobeless ; spikelets compressed. 
Flowering glume 5-nerved; spikelets many- 
flowered ... * MAS an dex 
Flowering glume 3-nerved; spikelets usually 
few-flowered wish er a 
Setaria. 
Flowering glume rugose ; bristles scabrous with erect 
teeth. 
Panicle cylindrical, short; spikelets solitary at 
the base of the bristles. Pale-green annual 
Panicle dense or interrupted, about 6in.; spikelets 
clustered near the base of the bristles. Taller 
and stouter Le 
Flowering glume smooth; panicle loosely cylindrical, 
about 2 in.; bristles scabrous with erect teeth 
189 
Danthonia 
Astrebla 
Agropyron 
Arundo 
Bromus 
Festuea 
Diplachne 
Sechedonorus: 
Distichlis 
Eleusine 
Triodia 
Eragrostis 
Poa 
glauca 
macrostachya 
viridis 
