28 



9. Florets close. Valve tips obtuse. _ Awns of lower valves 

 usually much shorter than those of the upper ... 



B. commutatus. 



Florets rather loose. Valve tips acute, entire or 



2-toothe(l. Awns nearly equal B. patulus. 



CHAETOBROMUS. 



1. Blades usually silky below. Lowest valve contracted into 



a bristle, 2i lin. long C. involucratus. 



Blades glabrous below. All the valves with a kneed 

 awn, 6-7 lin. long 2 



2. Culms erect, blades 2-5 iji. loiig. Lowest valve without 



side bristles C. dregeaniis. 



Culms ascending. Blades 6-10 in. long. All the valves 

 with side bristles C. schraderi. 



CHLORIS. 



1. Upper glume very broad, shortly bilobed, mucronate. 



Valves mucronate ... .,.; C. petraea. 



Glumes narrow, acute or mucronate, keeled. Valves 

 awned 2 



2. Awns as long as the valve or a little longer ... C. gayana. 

 Awns 3-6 times the length of the valve 3 



3. Rudimentary floret minute, on a long rachilla joint. 



C. pycnothrix. 



Rudimentary floret more than | the length of the fertile 



floret, on a rather short rachilla joint ... C. virgata. 



CYNODON. 



Culms many noded, with leaves mostly crowded at the 

 base. Ligule a ciliate rim. Rachilla produced ... 



C. dactylon. 



Culms 2-3 noded. Ligule membranous. Rachilla not 

 produced C. incompletus. 



DANTIIOMA. 



1. Spikelets 1^-2 inches long 2 



Spikelets i inch or less 3 



2. Blades 6-12 inches long, filiform, tapering to a long 



setaceous point D. macrantha. 



Blades 2-3 inches long, linear; tips filiform, obtuse. 



D. brachyphylla. 



