344 



THE AMERICAN 



of similar iiabit, have not been found except in 

 the immediate vicinity of salt water. 



We are, however, fully disposed to admit that 

 there is much plausibility in the supposition 

 that these peculiar lake shore plants are vestiges 

 of the vegetation which once flourished upon 

 the borders of the great inland seas which at a 

 comparatively recent time spread over the inte- 

 terior of this continent. 



We do not consider the question settled, but 

 present these researches as a contribution toward 

 a more comprehensive view of the question. 



NATIVE OAKS-No. 4. 



Black Oak (Qi 



There is greater confusion as to the common 

 names of different species of Oaks than with 

 respect to any other trees. Thus some half- 

 dozen trees are variously known as Black Oak, 

 lied Oak, Pin Oak, &c. This confusion arises 

 from the close resemblance of several species to 

 each other, the large variation as to form and 

 size of leaves and acorns in the same species, to 

 the tendency to hybridize among several species, 

 and to tlie want of close and discriminating 

 obsei-vation. 



The various forms to be met with every day 

 are frequently very puzzling, even to botanists. 

 We shall in this article attempt to describe and 

 iUu6trat« one of the commonest and most vari- 



able of our American oaks. The extreme forms 

 of this oak have been classified by botanists as 

 two distinct species, viz: Quercus tinctoria, 

 Bartram, and Quercus coccinea, Wang.; but 

 the best botanical authorities now unite these 

 as varieties of one species. Indeed, so numerous 

 are the variations presented in this species, both 

 in leaf and fruit, that we might with as much 

 propriety establish half a dozen species as two. 

 From a great number of specimens we have 

 selected a few of the more prominent to give 

 their chaijacters. 



[Fig. 212.] 



Black Oak IQuerciis cocctnea, var vulgaris.) 



A general description of the species may be 

 stated as follows: Leaves oval or oblong, or 

 sometimes, on young thrifty shoots, obovate in 

 outline, with about three divergent, slightly or 

 deeply cut, lobes, the lobes also sparingly and 

 sharply toothed; downy when young, and in some 

 varieties the under surfiice continuing downy 

 when old, upper surface glossy, the finer lobed 

 ones with long petioles or stems, thick and firm 

 when mature; acorns roundish or ovate, J to i 

 inch long, cup obconic and deep, or shallow and 

 nearly saucer-shaped. A good sized tree, 50 or 60 

 feet high, the bark smooth and mottled on young 

 trees, rough and blackish on old trunks; the 



