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-World 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 Ericaceaz (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 Monotropece, 

 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 



