CXLVII. GRAMIlfi;^. 909 



Spikelets all similar. 



Spikelets solitary, secund on a filiform or flattened 



inaiticulate rbachis l"!- Dimeria. 



Spilselets in open or contracted panicles. 



Racemes of spikelets in compound panicles. 

 Rhachis not fragile, 



Panicle spiciform silky ; spikelets 1-flowered ... 15. Imperata. 

 Rhachis fragile. 



Leaves petiolate ; spikelets 2-flowered 16. Spodiopogon. 



Leaves not petiolate ; spikelets 1-flowered. 

 Panicle much branched, open, silky. 



Spikelets awnless 17. Saccharum. 



Spikelets awned 18. Erianthus. 



Racemes of spikelets 2-nate, digitate or approximate 



on a short main axis 19' Polunia. 



Spikelets dissimilar. 



Spikelets of each pair differing in sex and structure or 

 (OyjAmnw) spikelets solitary not secund. 

 Spikelets sunk in pits of an articulate or fragile 

 rhachis. 

 Sessile spikelets unaccompanied by an upper 



spikelct or tlie pedicel of one ...;... 20. Opuiurus. 



Sessile spikelets accompanied by a dissimilar 

 pedicellate spikelet. 

 Lower invol.-glume ovate or oblong, flat, 



smooth 21. ROTTBOBLLIA. 



Lower iuvol.-glume globose, inflated, pitted ... 22. Manisuris. 

 Spikelets not sunk in nodes of the rhachis. 



Spikelets 3 on a very short uninodal inarticulate 

 rhachis, a sessile 2-flowered and 2 pedicellate 



enclosed in a pedunculate spathe 23. Apluda. 



Spikelets many or few on a plurinodal inarticulate 



rhachis. 



Spikelets many, 2-uate (rarely solitary"), in 



spike-like racemes which are solitary, 2-nate, 



digitate or approximate on a short main axis ; 



lower floret of the sessile spikelet male. 



Margin of lower in\ol.-glume of sessile 



spikelet inflexed 24. IsCH^Jiusf. 



Margin of lower invol.-glume of sessile 

 spikelet not inflexed. 



Spikelets 2-awned 25. Pogonatiierum. 



Spikelets 1-awned. 



Pedicellate spikelets floriferous 26. Lopiiopogon. 



Pedicellate spikelets reduced to 

 pedicels often glume-like. 

 Spikelets 1-2-flowered ; lower 

 invol.-glume cuneate-obovate or 

 obcordate, villous ; lodicules 0. 27. Apocopis. 

 Spikelets 1-flowered ; lower invol.- 

 glume lanceobite, often muri- 



culate; lodicules 2 28. Artiiraxon. 



Spikelets 2-flowered ; lower invol.- 

 glume ovate, beaked, transversely 



rugose; lodicules 2 29. Thelepogon. 



Spikelets in compound panicles or spike-like 

 racemes, variously disposed, 2-nate (rarely 

 3-nate) ; lower floret of all the spikelets 

 empty ; upper usually awued or reduced to 

 an awn. 

 Lower invol.-glume furnished with oil- 

 glands or ])eiiicillate tubercles close to 

 tiie keels ; spikelets not awned but often 

 beaked 30. Elionurup. 



