31 



5. Spikelets quite glabrous D. diversinervis. 



Spikelets not quite glabrous 6 



6. Racemes continguous, often resembling a solitary raceme. 



D. argyrograpta. 

 Racemes never contiguous except in a very young- 

 state 7 



7. Perennial 8 



Annual 9 



8. Culms rather stout i£-3 ft. Blades £-1 ft. by i-2 tin. 



D. eriantha. 

 Culms slender ^-1 ft. Blades setaceous, 2-6 in. long. 



D. selifolia. 



9. Pedicels terete, smooth D. tenuiflora. 



Pedicels angular, scabrid 10 



10. Pedicels shortly hairy near the tips. Spikelets obtuse, 



silky with clavate tipped hairs in very slender long- 

 racemes D. ternata. 



Pedicels glabrous. Hairs of spikelets not clavate ... 11 



11. Upper glume long acuminate, exceeding the upper valve. 



D. debilis. 

 Upper glume shorter than the upper valve 12 



12. Spikelets f-1 Lin. long. Lower glume 0. Valves closely 



nerved D. horizontalis. 



Spikelets 1-1^- lin. long. Lower glumes usually distinct. 

 Inner lateral nerves of the lower valve rather distant 

 from the middle nerve D. sanguinalis. 



DIPLACIINE. 



1. Blades |-2 in. long, very rigid, pungent ... D. paucinervis. 



Blades 3-9 in. long, flaccid or sub-rigid, never pungent 2 



2. Spikelets 2-3 flowered, reddish. Valves shortly awned. 



D. biflora. 



Spikelets 5-10 flowered, light green. Valves awnless or 



mucronulate 3 



3. Blades more or less flaccid. Ligules very short. Valves 



obtuse D. eleusine. 



Blades more or less rigid. Ligules up to 2^ lin. long. 

 Valves minutely emarginate D. fusea. 



EHRHARTA. 



1. Empty valves subulate -caudate, similar in outline, equal 

 or unequal, 2-4 times the length of the glumes ... 2 

 Empty valves not subulate-caudate, less than twice the 

 length of the glumes, or if subulate-caudate then the 

 culm is bulbous at the base, or the empty valves are 

 very dissimilar 5 



