Chast — Notes on Genera of Panlcese. IV. 105 



Alternate spikelets not facing in opposite ways (or if s<> 

 the lower of the pair aborted). 

 Spikelets (or the primary one of a pair) placed with the 

 back of the fruit turned away from therachis, usually 

 solitary. 

 First glume as long as the spikelet or nearly so. 



Spikelets in pairs, the secondary usually aborted, 

 sometimes wanting, strongly tuherculate-hispid 

 or uncinate at maturity, laterally compressed, 



in unilateral racemes 9. Echinolaena. 



Spikelets solitary, not tuberculate nor uncinate. 

 Inflorescence a single spike-like raceme; spikelets 

 swollen on the side toward the axis and fitting 



into alternate hollows 10. Mesosetum. 



Inflorescence a narrow panicle; spikelets swollen 

 on the side away from the rachis or at least 



more convex on that side 11. Leucophri/s. 



First glume obsolete or not over }£ the length of the 

 spikelet. 

 First glume and rachilla joint forming a swollen ring- 

 like callus below the spikelet, the glume reduced 

 to an adnate sheath of the rachilla joint; fruit 

 mucronate or shortly awn-pointed . . 12. Eriochloa. 

 First glume present or wanting but no ring-like 

 callus below the spikelet. 

 First glume present ; racemes racemose along the 



main axis 13. Brachiaria. 



First glume wanting; racemes digitate or sub- 

 digitate 14. Axonopus. 



Spikelets placed with the back of the fruit turned toward 



the rachis of the spike-like racemes, or pedicellate 



in panicles. 



Fruit long-acuminate, scarcely indurated, both glumes 



wanting; spikelets sessile, solitary in spike-like 



racemes, these re flexed or verticil late at maturity 



15. Reimarochloa. 

 Fruit not long-acuminate, indurated (if but slightly 

 indurated, both glumes present and inflorescence 

 paniculate). 

 First glume typically wanting; spikelets plano-con- 

 vex, subsessile in spike-like racemes . 16. Paspalum. 

 First glume present; spikelets usually in panicles. 

 Neither glumes nor lemmas awned . 

 Spikelet with a single fertile floret. 



Second glume and sterile lemma not indu- 

 rated, like the first glume in texture. 

 Glumes not equal nor entirely enclosing the 

 rest of the spikelet. 



