1886. ] BOTANICAL GAZETTE. 165 
is also a specimen in the Gray herbarium, which was collected 
not far from Philadelphia, Penn. 
This form appears, therefore, to be widely distributed in the 
eastern part of the northern United States. 
It has also been noticed in some of these localities for quite 
a number of years. Prof. H. G. Jesup speaks of having observed 
it at Missisquoi Bay in 1872, and so long ago as 1856 Prof. 
Caspary had occasion to notice an American Nuphar in the gar- 
ens at Kew, England, which I judge to have been this form. 
The study of this plant has led me to some very interesting 
conclusions. 
The first noticeable fact is, that it is immediately associated, 
and so far as I know or can learn, invariably associated with two 
other species, N. advena Ait. and N. Kalmianum Ait. 
he second fact is, that it appears almost exactly intermediate 
in all its parts between the two associated forms. The plate ac- 
companying this paper shows this very clearly. The stigmatic 
shield or disk of N. Kalmianum is distinctly star-shaped, the 
rays separated half way down, that of N. advena is crenate or 
waved at the margin, while the intermediate form has a shield, 
the margin of which is more deeply crenate than that of the one, 
and yet not so deeply cut as that of the other. I find a variation 
in the specimens as though the shields ran now towards one form 
and now towards the other in this particular. The fruit of the 
intermediate form, as a general thing, resembles that of N. Kal- 
mianum, but the neck and shoulders exhibit a tendency towards 
N. advena. The other organs speak for thermselves in the draw- 
ings, 
Curiously, too, the disk colors of N. advena and N. Kalmia- 
num when growing seem to blend in the other, being in the first 
pale red, in the second dark red, and in the third a beautiful 
bright red or crimson. This is uot seen in herbarium specimens, 
as in the process of drying they all become uniformly dark, 
The next fact is, that this intermediate form, as I found it in 
the Adirondacks, produces no fruit, or scarcely any. After a 
long and careful search in all the localities in that region, I could 
nd only a single imperfectly developed pericarp, and that had 
but two or three ripened seed in it, while the associated species 
bore an abundance of good fruit. The pollen of the intermediate 
form, also, when examined under the microscope, proved to be 
unsound, The same defect has been found in specimens of this 
plant gathered in Canada. Prof. Caspary, of Konigsberg, Prus- 
Sia, to whom flowers were sent by J. Fletcher, Esq., of Ottawa, 
reported to him that out of 155 grains of pollen examined he 
