46 THE TRUE GRASSES. 



duced to a pedicel) with 1-2 short 



awns 20. Rhytachne. 



2. Sessile spikelets awnless, the pedicellate 

 with long awns. . . . 21. Urelytrum. 

 II. Racemes digitate ; the iirst glumes of all the 

 spikelets long caudate-pointed. 22. Vossia. 

 C. Spikelets heterogamous, the sessile $ (rarely ? ), the pedi- 

 cellate $ , empty or wanting, very rarely all Q or all 

 pedicellate. Joints of raceme not strongly thickened, nor 

 with excavations for the reception of the spikelets. (The- 

 lepogon excepted.) 



a. Sessile spikelets two-flowered (Ischwmew). 



a. Racemes reduced to the terminal joint with 

 three spikelets, and enclosed by a sheathing 



leaf or bract 28. Apluda. 



/?. Racemes with many joints. 



L Pedicellate spikelets developed, flower- 

 bearing. 



1°. Sessile spikelets awnless, pedicellate 

 awned ; first empty glume three- 

 toothed 27. Lophopogon. 



2°. Sessile ' spikelets awned or with the 

 flowering glume at least mucronate- 

 pointed ; empty glumes not three- 

 toothed 24. Ischsemum. 



II. Pedicellate spikelets, very rudimentary, 

 or reduced to the pedicel. 

 1°. First sterile glume pectinate-fringed at 

 least at the base ; racemes solitary, 

 spikelets awnless. . . 25. Eremochloa. 

 2°. First empty glume not fringed ; racemes 

 two, closely appressed to each other; 

 spikelets usually awned. 26. Apocopis. 

 3°. First empty glume not fringed, trans- 

 versely wrinkled and tuberculate ; 

 racemes digitate ; spikelets awned. 



23. Therepogon. 



b. Sessile spikelets, one-flowered ( Evand ropogonere). 

 Flowering glume of the pedicellate spikelets awn- 

 less. 



