KEY TO THE SPECIES. A. Sessile spikelets all similar. B. Racemes of many spikelets. C. Peduncle of racemes enclosed in spathiform leaf-sheaths. D. Joints of rachis and pedicels of upper spikelets slender and tips obliquely truncate. Racemes solitary, pedicelled spikelets similar to the sessile, glume 1 of sessile spikelets pitted. 1. A. foveolatus. DD. Joints of rachis and pedicels of upper spikelets clavate or trumpet-shaped and tips cupular with toothed margins. Racemes binate, pedicelled spikelets differing from the sessile, glume I of the sessile spikelets deeply channelled. 2. A. pumilus CC. Peduncle of racemes not enclosed in spathiform leaf-sheath. Racemes many, fascicled or panicled, glume I of sessile spikelets glabrous and pitted. 3. A. pertusus. Racemes many and whorled in the panicle; glume I of sessile spikelets muricate on the margins. 4. A. squarrosus. BB. Racemes of 3 spikelets on the capillary whorled branches of an erect panicle. Pedicels of upper spikelets half as long as the sessile spikelets or longer. Leaves broad. Leaf-sheaths covered densely with bristly hairs. 5. A. asper. Leaf-sheaths covered with soft hairs. 6. A. Wightianus Pedicels of upper spikelets not half as long as the sessile spikelet. Leaves glabrous and narrow 7. A. monticola. AA. The lowest one or more sessile spikelets in all racemes, or at least in one or two, differing from all those above. Racemes digitate, rarely solitary, spikelets all alike in form but differing in sex. Pedicel 1/3 as long as the sessile spikelets; nodes usually glabrous; ligule usually short and membranous. 8. A. caricosus. Pedicel 1/2 as long as the sessile spikelets; nodes bearded; ligule large and membranous. 9. A. annulatus. Racemes solitary; lower sessile spikelets very unlike the pedicelled or upper spikelets which are cylindric. Margin of glume 1 of the pedicelled spikelet unequally winged; ligule is a broad truncate membrane. 10. A. contortus. Racemes two, both sessile, or one sessile and the other pedicelled on a peduncle which is more or less sheathed by a proper spathe, divaricate or deflexed. Leaf base broad and cordate 11. A. Schoenanthus. _N.B._--This genus is now split into several separate genera, each subgenus being raised to the rank of a genus. But in this book the nomenclature adopted in Hooker's Flora of British India is followed.