10 
CL VII. GRAMINEiE (Stapf). 
spatheate fascicles or fastigiate pani- 
cles ; spikelets 1 -flowered ; coarse 
tall grasses ... ... 20. Ccelorrhachis. 
Racemes solitary and terminal on 1- or 
few-noded culms ; sessile spikelets 
2 -flowered ; back of lower glume 
usually transversely rugose ... 21. Rhytachne. 
e. Saceharastrae. 
Rhachis of racemes continuous at the nodes and tough, 
or tardily disarticulating, all spikelets pedicelled. 
Racemes in spike-like or thyrsoid solitary panicles, 
rhachis quite tough ; spikelets muticous ; 
glumes delicate or somewhat firm at the base... 22. Imperata. 
Racemes in large, often reddish or brownish panicles, 
rhachis tough or tardily disarticulating ; spike- 
lets awned ; glumes chartaceous to coriaceous 23. Miscanthidium. 
Rhachis of racemes readily disarticulating ; spikelets 
paired, one sessile, the other pedicelled. 
Glumes coriaceous or chartaceous throughout ; pani- 
cles narrow, fulvously to rufously villous or 
tomentose ; spikelets always muticous, the 
pedicelled $ 24. Eriochrysis. 
Glumes membranous or chartaceous to subcoria- 
ceous at the base ; panicles wide, often thyrsoid, 
more or less plumose and silvery ; spikelets 
usually awned, rarely mucronate or awnless ; 
awn a straight, rarely bent not twisted bristle 25. Saccharum. ^ CJ- 
/. Polliniastrae. 
Spikelets dorsally compressed ; callus short, obtuse ... 26. Eulalia. 
Spikelets subterete ; callus long, pungent ... ... 27. Homozeugos. 
g. Sorghastrae. 
Spikelets dorsally compressed (at least when in flower) ; 
lower glume of the fertile spikelets firmly charta- 
ceous to coriaceous. 
Spikelets in threes, one of them fertile, or in racemes 
of 2-8 pairs ; the pedicelled 3 , neuter or if quite 
suppressed then at least the pedicels present . . . 28. Sorghum. 
Spikelets solitary ... ... 29. Cleistachne. 
Spikelets laterally more or less compressed. 
Racemes of many pairs of spikelets ; primary 
branches of panicle in whorls of 6 to 20 ... 30. Vetiveria. 
Racemes usually reduced to 1 sessile $ and 2 pedi- 
celled 3 or barren spikelets, rarely of 2 or more 
but always few pairs ... ... ... ... 31. Chrysopogon. 
h. Arthraxonastrae. 
Only tropical African genus ... ... ... ... 32. Arthraxon. /6 
i. Hypogyniastrae. 
Only tropical African genus ... ... ... ... 33. Hypogynium. 
