280 BULLETIN 772, TJ. S. DEPARTMENT OF AGRICULTURE. 



what clustered in the axils of the foliage leaves. Species one, in 

 the tropical regions of the world. 



Type species: Manisuris granularis Swartz. 



Rytilix Raf., Bull. Bot. Seringe 1: 219. 1830. Rafinesque cites "Manisuris 

 granularis et Myurus Auct" and lists one species Rytilix glandulosa. The first 

 species cited is chosen as the type. 



Hackelochloa Kuntze, Rev. Gen. PI. 2 : 776. 1891. Kuntze restores Manisuris 

 to its Linnsean sense and, overlooking Rytilix Raf., proposes Hackelochloa for 



Manisuris Swartz, with H. granu- 

 laris, based on Cenchrus granularis, 

 as the type. 



Rytilix granularis (L.) 

 Skeels (fig. 169) is a tropical 

 weed which extends into the 

 United States from Florida 

 to Arizona. The little pitted 

 globose spikelets are very char- 

 acteristic. 



FIG. 169. Rytilix granularis. Plant, X * ; a single raceme, X 2 ; two yiews of a pair 

 of spikelets with joint of rachis and pedicel grown together, X 5. 



14. TRIPSACEAE, THE CORN TRIBE. 



141. TBIPSACUM L. 



Spikelets unisexual ; staminate spikelets 2-flowered, in pairs on one 

 side of a continuous rachis, one sessile, the other sessile or pedicellate, 

 similar to those of Zea, the glumes firmer ; pistillate spikelets single 



