NORTH AMERICAN FLORA. 267 
the species and the types increasing as we proceed southward, 
but about the same numerical proportion would hold. 
But, more interesting than this numerical preponderance — 
which is practically confined to the trees and shrubs — will 
be the extra-European types, which, intermixed with familiar 
Old-W orld forms, give peculiar features to the North Amer- 
ican flora, — features discernible in Canada, but more and 
more prominent as we proceed southward. Still confining 
our survey to the Atlantic district, that is, without crossing 
the Mississippi, the following are among the notable points: 
1. Leguminous Trees of peculiar types. Europe abounds 
in leguminous shrubs or under-shrubs, mostly of the Genis- 
teous tribe, which is wanting in all North America, but has no 
Leguminous tree of more pretence than the Cercis and Labur- 
num. Our Atlantic forest is distinguished by a Cercis of its 
own, three species of Locust, two of them fine trees, and two 
Honey Locusts, the beautiful Cladrastis, and the stately Gym- 
nocladus. Only the Cercis has any European relationship. 
For relatives of the others we must look to the Chino-Japanese 
region. 
2. The great development of the Lricacew (taking the 
order in its widest sense), along with the absence of the Eri- 
ceous tribe, that is, of the Heaths themselves. We possess on 
this side of the Mississippi thirty genera, and not far from 
ninety species. All Europe has only seventeen genera and 
barely fifty species. We have most of the actual European 
species, excepting their Rhododendrons and their Heaths, — 
and even the latter are represented by some scattered patches 
of Calluna, of which it may be still doubtful whether they are 
chance introductions or sparse and scanty survivals; and 
besides we have a wealth of peculiar genera and species. 
Among them the most notable in an ornamental point of 
view are the Rhododendrons, Azaleas, Kalmias, Andromedas, 
and Clethras; in botanical interest, the endemic Monotropea, 
of which there is only one species in Europe, but seven genera 
in North America, all but one absolutely peculiar; and in 
edible as well as botanical interest, the unexampled develop- 
ment and diversification of the genus Vaccinium (along with 
