'26 IiBARDBTS. 



normally aquatic, I shall doubtless found aggregates; for I 

 apprehend clearly the possibility, even the probability, that cer- 

 tain species which in their aquatic floating state present no char- 

 acters upon which one may separate them, will in their riparian 

 phases, when these are found, display their specific differences. 



Here, then, is work for many a future generation of botanists, 

 and most interesting work ; but it must be begun in the field, 

 and carried on there, patiently and persistently. 



In the diagnoses that follow I decline to make any use or 

 application of old varietal names, such as ierrestris, emersa, 

 Muhlenbergii, natans, and others. No one knows, and perhaps 

 no one ever will know, just what the forms or states or phases 

 were to which the authors applied the names ; and to use them 

 iguorantly of their first application is but to make confusion 

 worse confounded. 



It also seems necessary where aquatic, riparian a»d terrestrial 

 phases of a species are known, to describe each in a separate 

 paragraph, so very different are the characters of stem, leaf and 

 inflorescence in the several phases. There is no other conve- 

 nient way of making a full diagnosis of such species ; for, as 

 must be obvious to every one, these are states or phases, not 

 varieties ; so that to give them any kind of separate rank, or to 

 assign them names as such would be to misrepresent the facts in 

 the case, and therefore to be unscientific. 



P. FLUITANS. Polygonum fluitans, Baton in Eat. & 

 Wright, 368. Aquatic. Stems very slender, the submerged in- 

 ter nodes 3 to 6 inches long, the floating ones 1 to IJ inches, 

 exceeded by the remarkably slender petioles, these commonly 2 

 inches ; leaf -blades elliptical to elliptic-oblong, IJ to 4J inches 

 long, never subcordate, always tapering at base though abruptly 

 spike solitary, short-cylindric, slender-peduncled : bracts broad- 

 ovate, acute, glabrous. 



Frequent in northern lakes from Maine and across Lower Canada 

 to Wisconsin and south to New Jersey. Fernald's Aroostook Co., 

 n. 95 ; a series of sheets from northern New York collected at 

 various stations in 1879 and 1888 by L. F. Ward (these in U. S. 

 Herb.), and some fine specimens taken by Mrs. C. F. Baker, at 

 St. Croix Falls, Wisconsin, in 1899 — all represent well this east- 



