OUR AMPHIBIOUS PERSICARIAS 5 
meant to imply that Dr. Gray failed to see that P. amphibia though 
it has its terrestrial phase never has spreading herbaceous tips 
to the ochreae, has different pubescence and different inflorescence, 
even compared to the land phase of the American P. Hartwrightw 
which latter, as a matter of fact, has not till lately been reported 
in its aquatic phase. A careful study of the various phases of 
the Persicarias described by Dr. Greene in his classical researches 
on that most difficult group of plants—all the more so since so 
little, and often such poor specimens of plants have until lately 
been collected in that group with little or no data,—will reveal 
the fact that the plants discovered by him differ from one another 
greatly in their respective phases. In other words the European 
P. amphibia differs from the American P. Hartwrightw in its two 
phases, aquatic and terrestrial, compared with one another in 
. each phase. P. amphibia has, moreover, been shown to have a 
third or xerophytic stage first pointed out by Massart. P. fluitans 
Eaton is not yet known in its terrestrial stage, which may not be 
present, but its aquatic form resembles in no way that of either 
P. Hartwrightii or P. mesochora. ‘The latter known only heretofore 
in the aquatic phase, I have found in terrestrial and riparian 
forms in the lakes near the University. 
P. coccinea Muhl. has its several phases more closely related 
usually, and often succeeding one another in the vicissitudes con- 
sequent on drying up of pools later in the season, but these forms 
differ widely from the respective phases of the other species men- 
tioned. When Dr. Gray, therefore, published Polygonum Hart- 
wrightii we may expect that as an experienced phytologist, and not 
at all a reckless one, that he must have seen that without the aquatic 
form even it was not to be confounded with the terrestrial form of 
P. amphibium. As to the validity of Polygonum fluitans Eat. the 
author of the name spent several years studying the plant in its 
native habitat, his description is unmistakable, and he distin- 
guishes it perfectly from P. amphibrum described on the same 
page, and yet to make an easy exit out of a difficult taxonomic 
problem the modern manual makers have been invariably content 
‘to jumble together a number of plants totally different by constant 
and definite characters, and excuse ignorance of them under the 
often used phrase “a very variable species.’’ When, however, 
the student of ecology is tempted to sit in judgment on the taxon- 
omists for wantonly and recklessly multiplying names of plants, 
