52 THE TRUE GRASSES. 



Steud., Microstegium Nees). Spikelets slightly hairy, 

 usually only upon the callus, rarely upon the keel. 

 Leaves lanceolate, much narrowed at the base. 



14. (77) Spodiopogon Trin. Racemes with long pedi- 

 cels, usually with only two to three pairs of spikelets ; 

 first empty glume keelless, strongly 5-9-nerved. Spike- 

 lets somewhat laterally compressed, awned from a deep 

 notch in the flowering glume. 



Species five, in Asia Minor, Hindostan, China, 

 Amur, and Japan. 



15. (77a) Polytrias Hack. A low, prostrate grass with 

 shining, red-brown, hairy racemes, each joint of the 

 rachis bearing two sessile and one pedicellate spikelet. 

 Flowering glumes with a terminal awn. 



Species one (P. prcemorsa Hack.), in Java. 



16. (79) Pogonatherum Beauv. (Homoplitis Trin.). 

 Spikelets very small, the second empty glume and the 

 flowering glume with long delicate awns. Anthers two. 

 Delicate grasses. 



Species two, in the East Indies ; one (P. saccharoideum 

 Beauv.) extends to Japan. 



3. Sub-tribe Rottbcellieae. 

 Joints of the rachis and the spikelets usually naked. 



17. (86) Ratzeburgia Kunth. Racemes (false spikes) 

 linear, flattened. Joints of the rachis curved above ; 

 first empty glume reticulately ribbed. 



Species one (i?. pulclierrima Kunth), on the river 

 Irawaddi. 



18. (84) Rottbcellia L. False spikes cylindrical or 

 slightly compressed ; first empty glume coriaceous, 

 covering the excavation in the rachis-joint ; spikelets 

 awnless. 



A polymorphous genus with the following sub- 

 genera : 



Sub-genus I. Coelorhachis (Brongn. as a genus, 

 Stegosia Lour.). Racemes solitary and terminal upon 

 the culm and its branches, articulate and joints read- 

 ily separating ; joints of the rachis hollow at the apex, 



