26 ; LEAFLETS. 
normally aquatic, I shal] doubtless found aggregates; for | 
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 /errestris, emersa, 
Muhlenbergit, 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 
ignorantly of their first application is but to make confusion 
worse confounded. 
It also seems necessary where aquatic, riparian aad 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, Eaton in Eat. & 
Wright, 368. Aquatic. Stems very slender, the submerged in- 
ternodes 3 to 6 inches long, the floating ones 1 to 14 inches, 
exceeded by the remarkably slender petioles, these commonly 2 
inches ; leaf-blades elliptical to elliptic-oblong, 14 to 44 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- 
