l6. GRAMINEAE 85 



43. Lower outer glume awned or tailed, at least in the stalked spikelets. . 44 

 Lower outer glume neither awned nor tailed, rarely tailed in the terminal 



spikelet only 46 



44. Lower outer glume with a long tail (or soft awn). Racemes digitate. 



Aquatic herbs. — Species i. Central Africa. Forming the chief element 

 of the grass-barriers (sudd) of the upper Nile, Vossia Wall, & Griff. 

 Lower outer glume with i — 2 short awns, or in the stalked spikelets with a 

 long awn, in the sessile awnless. Racemes soUtary or arranged in 

 racemes 45 



45. Lower outer glume with i — 2 short awns. Joints of the rachis horizontally 



truncate without an appendage. — Species 7. Central Africa. Used 

 for plaiting-work. {Rhytidachne Hack., including Jardinea Steud.) 



Rhytachne Desv. 

 Lower outer glume in the sessile spikelets awnless, in the stalketl ones with 

 a long awn or tail. Joints of the rachis obliquely truncate with an 

 appendage at the tip. — Species 5. Central and South Africa. 



Urelytrum Hack. 



46. Lower outer glume globular, pitted. Leaves cordate at the base. — 



Species i. Tropics. Used in medicine. (Including Hackelochloa O. 



Ktze.) Manisuris Swartz 



Lower outer glume more or less ovate, fiat or rounded on the back. . 47 



47. Stalked spikelets reduced to the adnate pedicel and therefore apparently 



absent. — Species i. Northern East Africa. (Under Rotthoellia L. fil.) 



Ophiurus Gaertn, 



Stalked spikelets containing a male flower or reduced to empty glumes. — 



Species 15. (Including //djmar/Ärjß R. Br.) . . RottboelUa L. fil. 



48. (42.) Sessile spikelets 2-flowered, the lower flower male, the upper male 



or hermaphrodite. Stalked spikelets i — 2-flowered or reduced to 



empty glumes. 49 



Sessile spikelets i-flowered, rarely all spikelets stalked and i- or {Imperata) 

 2-flowered. 5^ 



49. Sessile spikelets containing 2 male flowers, stalked spikelets a male and a 



female or hermaphrodite flower. Outer glumes of the sessile spikelets 

 awned. Flowering glumes awnless. Spikelets in compound racemes. 

 Leaves lanceolate. — Species i. Madagascar. Cyphochlaena Hack. 



Sessile spikelets containing a male and an hermaphrodite flower. Flowering 

 glumes of the sessile spikelets nearly always awTied. [Subtribe 



ISCHAEMINAE.] 5^ 



50. Racemes reduced to the 3 terminal spikelets, surrounded by sheathing 



bracts, fasciculate ; fascicles arranged in panicles. Stamens 2 — 3. — 

 Species i. Islands of Reimion and Socotra. Used as an ornamental 



plant Apluda L. 



Racemes consisting of numerous pairs of spikelets, sohtary or digitate ; 

 one spikelet of each pair sometimes reduced to the pedicel. Stamens 

 3 31 



