30 



i7. Valves loosely villous, hairs not in tufts. Lower-sheaths 

 pubescent or tomentose and pruinose, but not covered 



with a coat of wool D. elephantina. 



Valves with distinct tufts of hairs. Sheaths glabrous 

 except sometimes near the mouth or at the very 

 base 18 



18. Sheaths woolly at the mouths. Hair tufts of valve 3 on 



each side at the base of the lobes, and equal to them. 



D. papposa. 



Sheaths glabrous or almost so. Valve tufts of hairs 



forming a dense straight transverse fringe at or near 



its middle, or in an oblique transverse fringe near 



the base, or submarginal on each side 19 



19. Culms and leaves very robust. Tufts of hairs a trans- 



verse fringe at or near the middle of the body of the 



valve D. cincta. 



Culms and leaves more slender, firm. Fringe of hairs 

 siib-marginal or basal 20 



20. Glumes 1 or lower sub- 3 nerved. Tufts of hair in an 



oblique fringe near the base of valve. Lobes of valve 



almost wholly adnate to the awn D. macowani. 



Glumes 5-3 nerved. Valve tufts of hairs submarginal; 

 lobes free from the awn 21 



21. Blades wiry. Lobes of the valve mucronate ... D. dura. 

 Blade.=5 filiform. Lobes of the value acute, with a slender 



side bristle D. stricta. 



DIGITARIA. 



1. Racemes rather lax, compound near the base, villous 



with long silky, often purplish, hairs, conniving into 



a brush-like point 2 



Racemes simple or nearly so. Spikelets glabrous or 

 covered with fine adpressed hairs 3 



2. Racemes sessile or subsessile, sub-digitate 



D. tricholaenoides. 

 Racemes peduncled, in a scantily branched panicle. 



D. flaccida. 



3. Racemes setose. Spikelets surrounded by stiff hairs 



from tips of the pedicels D. diagonalis. 



Racemes not setose 4 



4. Racemes solitary, dense, densely villous 



D. monodactylon. 

 Racemes 2 to many 5 



