GRAMINEAE 



AA. Spikelets dorsally compressed or rounded, binate at each node or 

 ternate at the terminal node of the rachis, rarely solitary 

 through the suppression of the pedicelled spikelets. 

 B. Spikelets all fertile and alike (the pedicelled spikelet of the pair 

 sometimes reduced in Microstegium). 

 C. Rachis continuous; the spikelets falling from it. 



Spikelets in a broad fan-shaped panicle, or in several to 



many fascicled racemes 70. 



Spikelets in a narrow spike-like panicle 71 . 



CC. Rachis jointed; the joints falling with the sessile spikelets 

 attached (except in Spodiopogon cotulifer). 

 D. Racemes numerous, from an elongated common axis. 



Racemes subsessile, several-many-jointed, in a large 



plumose panicle 72 . 



Racemes peduncled, few-several-jointed 73. 



DD. Racemes many to 1 on a shortened common axis. 

 Racemes digitate or fascicled. 



Culms erect: blades linear 74. 



Culms straggling: blades lanceolate 75. 



Racemes solitary 76 . 



BB. Spikelets not all fertile, frequently different also in shape, size 

 and awns. 



E. Rachis joints and pedicels more or less stout; or 

 if slender, the blades lanceolate, cordate. 

 F. Fertile lemma usually awned: rachis joints and 

 pedicels villous or ciliate (except in Art- 

 hraxon hispidus). 



Joints and pedicels stout, triquetrous 77. 



Joints and pedicels slender, linear 78. 



FF. Fertile lemma typically awnless: joints and 

 pedicels usually glabrous. 



G. Racemes usually corymbose-digitate 79. 



GG. Racemes solitary. 



H. Sessile spikelet globose; pedicelled 



spikelet conspicuous: annual 82. 



HH. Sessile spikelet oblong; pedicellate 

 spikelet reduced. 

 Sessile spikelets sunken in the excava- 

 tions of the thickened rachis. 

 Pedicelled spikelets similar to the 



sessile: rachis tenacious 80. 



Pedicelled spikelets not similar to 



the sessile: rachis fragile 81. 



Sessile spikelets not sunken in the 



excavations of the thickened rachis. 83. 

 EE. Rachis joints and pedicels slender: blades narrow or 

 broad, but never cordate. 

 I. Racemes paniculate or corymbose-digitate. 



Joints and pedicels, especially the upper ones 

 of the raceme, longitudinally grooved. 



Racemes several-many-jointed, digitate 84. 



Racemes 1-5-jointed, paniculate 85. 



Joints of the pedicels not longitudinally grooved 86. 

 II. Racemes binate or solitary. 



476 



Miscanthus 

 Imperata 



Saccharum 

 Spodiopogon 



Eulalia 



Microstegium 



Pogonatherum 



Ischaemum 

 Arthraxon 



Phacelurus 



Hackelochloa 



Hemarthria 



Rottboellia 



Eremochloa 



Bothriochloa 



Capillipedium 



Sorghum 



