﻿Nash : Genus Syntherisma in North America. 291 



are three, in others four scales, and it often happens, especially in 



l 



one or two species, that spikelets of both three and four scales 

 occur indiscriminately in the same raceme, as mentioned above in 

 connection with Paspalum bifidum. 



So it will be readily seen that Paspalum is as closely related to 

 Panicum, through Paspalum bifidum and Dimorphostachys as is 

 Syntherisma, and if one is to be separated, to be consistent the 

 other must be also. Our own view is that Syntherisma is more 



nearly related to Paspalum than to Panicum, and if its union with 

 either genus were desirable it would certainly be with the former 

 and not with the latter. 



All the other genera above enumerated are in some form 



cry 



distin- 



guished from Panicum by having the first as well as the second 

 flower perfect ; Ichnanthus has a spikelet similar to that in some 

 forms of Panicum, but the fourth scale is pitted or winged at the 

 base, sometimes rather obscurely so ; Trichdaena differs from 



Pa 



s pal it i 



more prominent or important than those distinguishing Syntfwc- 

 isma; yet all these genera are considered distinct, while such as 



as is 



a (certainly as close to Oplisn 



Hymenackne and Ptychophy 



are relegated to that convenient repository of many modern 

 authors, Panicum, although certainly as worthy of specific rank as 

 are those previously mentioned. Would not then consistency de- 

 mand that all be united with Panicum, or if one or more be sepa- 

 rated, then all? The answer can hardly be other than in the 

 affirmative. 



There is one grass in this country and adjacent Mexico which 

 has characters that ally it to the genus we have under considera- 

 tion, and would at first sight make it appear intermediate between 

 this and Trichachne. Reference is made to what has been called 

 Panicum tencrrimum of Kunth. The spikelets do resemble some- 

 what those of Syntherisma, but the habit of the plant and the 

 short appressed branches of the inflorescence make evident its 

 closer relationship to the Panicum lacnanthum of Torrey. 



The results here attained have been reached after an examina- 

 tion and study of the material in my own herbarium, and in the 



