86 l6. GRAMINEAE 



51. Stalked spikelets reduced to the pedicel. Lower outer glume tuberculate. — 



Species i. Abyssinia Thelepogon Roth 



Stalked spikelets i — 2-flowered or reduced to empty glumes. — • Species 7. 

 Tropical and South Africa. Some are used as fodder- or garden plants. 



Ischaemum L. 



52. Spikelets all ahke, hermaphrodite. [Subtribe saccharinwe.] • • • 53 

 Spikelets of two kinds, the sessile hermaphrodite, rarely female, the stalked 



ones male or neuter, sometimes reduced to the pedicel. [Subtribe 



ANDROPOGONINAE.] 6o 



53. Rachis of the raceme jointed 54 



Rachis of the raceme not jointed 57 



54. Racemes more or less palmately arranged on a short main axis, rarely 



solitary 55 



Racemes arranged in panicles along a slender main axis, silky. Spikelets 

 in pairs 5^ 



55. Spikelets solitary on the branches of the inflorescence, all sessile. Flowering 



glumes awned from the back. Leaves cordate-lanceolate. — Species 5. 



Tropics Arthraxon Beauv. 



Spikelets in pairs on the branches of the inflorescence, one sessile, the other 

 stalked. Flowering glumes awned from the tip, rarely awnless. Leaves 

 linear or lanceolate with a narrow base. — • Species 5. South and East 

 Africa, Madagascar and the neighbouring islands. (Including Eidalia 

 Kunth) Pollinia Trin. 



56. Flowering glume produced into a bristle or awn. — Species 5. South Africa, 



southern Central Africa, and Algeria. Some are used as ornamental 



plants or for plaiting mats. Erianthus Michx. 



Flowering glume unarmed like the other glumes. — Species 5. One of them 

 (5. ojjicmarum L., sugar-cane) known only in a cultivated state. It 

 is used for the manufacture of sugar, syrup, rum, and wax, also as a 

 vegetable and a fodder-plant Saccharum L. 



57. Spikelets in pairs along the rachis of the raceme, awnless. Outer glumes 3, 



membranous, silky. Stamens i — 2. — Species i (/. cylindrica P. 

 Beauv.) Sometimes a noxious weed in plantations, but also used for 

 paper-making, and as a fodder-, medicinal or ornamental plant. 



Imperata Cyr. 

 Spikelets scattered along the rachis of the raceme, awned. ... 58 



58. Outer glumes 3, the two lower stiff. Flowering glume very small, ending 



in a long awn. Panicle spreading, hairy. — Species 2. Central Africa. 



Cleistachne Benth. 



Outer glumes 2. Flowering glume rather large, with a usually short awn 



in a terminal notch or on the back. Panicle spike-Uke. , . -59 



59. Stigmas projecting at the tip of the spikelet, short-haired all roimd. Outer 



glumes awnless, rarely with a short awn. (See 41.) Alopecurus L. 



