430 CXLII. GEAMINEiE. 



Lowest flowering glume neuter or male. 



Flowering glume and palea (the latter 



generally flattened) hardening in fruit. 



Q'he 2 lowest glumes generally not very 



dissimilar and almost exactly opposite. 



Inflorescence almost every form of panicle. 

 (In the subgenus Digitaria the lowest 



glume is generally very small, and the 



spikelets are arranged mostlv in pairs on 



one side of digitate or clustered rachis. In 



subgenus Orthojyogon tlie 3 lowest glumes 



are generally long pomted and strongly 



nerved) 3. Panicum. 



Spikelets on very short, few-flowered ra- 

 cemes, which are more or less deeply 



immevsed in alternate hollows on one side 



of the thickened rachis of the solitary, 



terminal spike. — Leaves flat. Otherwise 



as in Panicnm 4. Stenotapheum. 



Anomalous Genus. — Axis of the spikelet pro- 

 longed into a delicate filament (rudimen- 

 tary glume). All the glumes and paleae 



mucronate, the flowering ones not harden- 

 ing conspicuously in fruit. Both flowers 



contain scales. Paleae remarkably eared on 



each side towards the base. — Spikelets 



arranged in digitate racemes. Leaves 



generally hairy 5. Bluffia. 



tt Spikelets involucrated at their base. — The 



involucre is extremely short, little more 



than a beard in Tricholcena. 

 Involucre of uniform bristles, persistent, 



principally placed on one side of the 



spikelet. Flowering glume and palea 



much hardened in fruit, and the glume 



generally wrinkled on its outer sm'face. 



— Spikelet generally gibbous 6, Setaeia. 



Involucre persistent, of 2 forms, some of 



the bristles being feathered and some 



simply scabrous, completely surrounding 



the spikelet. 2 lowest glumes very small. 



Anthers penicillate. Grain obovate . . 7. Pexicillaeia. 

 Involucre extremely short, beard-like, falling 



off* with the spikelet, which is silkily hairy, 



terminal and solitary on a long, slen- 

 der pedicel. Glumes distant and alter- 

 nate, the 2 lowest extremely dissimilar. 



Flowering glumes very small 8. Teichol^NA. 



Involucre (falling off with solitary spikelet) 



composed of scabrous bristles, uniform 



in structure, unequal in length, 1 bristle 



extremely long. — Inflorescence densely 



spicate. Styles united at base .... 9. Gtmnotheix. 

 Involucre embracing 2-3 spikelets, composed 



of 2 kinds of bristles, some long feathered 



