A. Gray—North American Flora. 329 
world forms, give peculiar features to the North American 
flora,—features discernible in Canada, but more and more 
prominent as we proceed southward. Still confining our sur- 
three species of Locust, two of them fine trees, and two Honey 
TAot 
Locusts, the beautiful Cladrastis, and the stately Gy . 
dodendrons and their Heaths,—and even the latter are repre- 
sented by some scattered patches of Calluna, of which it may be 
still doubtful whether they are chance introductions or sparse 
evelopment and diversification of the genus Vaccinium (along 
With the allied American type, Gaylussacia) will attract atten- 
lon, It is interesting to note the rapid falling away of Hricacese 
westward in the valley of the Mississippi as the forest thins out. 
3. The wealth of this flora in Composite is a most obvious 
feature; one especially prominent at this season of the year, 
when the open grounds are becoming golden with Solidago, and 
= eariier of the autumnal Asters are beginning to blossom. 
very few Asters and only two Solidagoes, no Sunflowers and 
hardly anything of that tribe. Our Atlantic flora surpasses all 
