64 Statistics of the Flora of the Northern States. 
mon to the Old and the New Worlds; and the same species is as 
hkely to occur at any two stations within the arctic circle as at 
any other two stations equally distant. We naturally look 
northward for the connection of our flora with that of the Old 
World; and as we meet with United States Serie identical 
with those of Europe, we are interested to know whether they 
range northward into or near to the area of common northern 
vegetation. The data now in our possession furnish the follow- 
ing results. 
a our species common to Europe, we know only five which 
not occur north of the a parallel of latitude, or which 
hasily cross this line. These 
Callitriche pedunculata. Cyperus rotundus. . 
uncus maritimus. Carex flacca. 
Convallaria majalis. 
The first of these has doubtless been overlooked. The second 
is a little-known plant with us, and the identification is not per- 
fect. The fourth is a tropical s ecies, and evidently an immi- 
ant niet _ southern United States as well as into southern 
urope,. is it impossible that our Nut-Grass may again be 
spaahealty Getcrns ed from Cyperus rotundus. The fifth is 
here at only in New Jersey, between lat. 40° and 41°. Un- 
less it has been overlooked in the Northern States (which seems 
walikely), or unless our plant has been wrongly referred to the 
variable Carex flaca, it affords a remarkable instance of the local 
occurrence here of a species which is widely diffused in the Old 
World. Itseems not likely to have been introduced from Europe. 
The third is the most remarkable case; that of the Lily of the 
Valley (Convallaria maalis). ‘This species—or one which I could 
not in any respect distinguish from it on a comparison of living 
specimens—abounds in the higher ‘Alleghanies of Nort 
lina, I believe also in those of Georgia, and it extends north 
to the Peaks of Otter in Virginia, lat. 874°, at an altitude of 
4000 feet; but it is not known to occur anywhere beyond this; 
while in Western Europe it extends nearly to lat. 70°. It isnot 
a eet ea could well have escaped observation in the North- 
ern. 
whe. allowing 15 species are not known to occur north of lat. 
Myosurus minimus. Polygonatum latifolium. 
Subularia aqnatica 
Centunculus minimus. Carex vulpina. 
Veronica officinalis, “  muricata. 
Myosotis ary ensis. 7 7 levigata. 
Salicornia mucronata ? S$ 
Polygonum dumetorum, 
Castanea vesca, var. 
