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THE AMERICAN NATURALIST [Vol. XLVI 



no such radical differences within the area as those, for instance, 

 between the Southern California desert and the Redwood belt 

 of the coast region of the same state. The most important fea- 

 ture of this Eastern area is the great development of the dicoty- 

 ledonous forest trees. Probably nowhere outside the tropics is 

 to be found a richer forest flora, and the trees, both by their 

 size and variety, constitute a truly magnificent forest. This 

 forest reaches its finest development in the Southern Alleghenies 

 of western North Carolina and in parts of the Ohio and Missis- 

 sippi Valleys. Unlike the northern forest belt and the forests 

 of most parts of Europe, this forest is composed of a great many 

 species intermingled. It is stated by Harshberger that probably 

 the richest forest vegetation in the north temperate zone is found 

 in the lower Wabash Valley in Illinois, where one hundred and 

 seven species of trees occur. In an area of less than a square 

 mile in extent seventy-five species of trees were counted. 



While many of these trees belong to European genera, e. g., 

 Poplar, Beech, Birch, Oak, Elm, Ash, etc., many genera are 

 absent from the European forests. Such, for example, are the 

 gums (Liquidambar and Nyssa), Magnolias, Tulip trees (Lirio- 

 dendron), Hickories, Locusts (Gleditschia and Robinia), the Cy- 

 press (Taxodium), etc. Some of these trees reach really gigan- 

 tic size, in regard to which Harshberger gives some striking fig- 

 ures. Thus a Red Oak is cited which was seven feet in diameter, 

 with a height to the first branch of ninety-four feet, and a total 

 height of one hundred and eighty-one feet. A White Oak and 

 Bur-Oak of nearly equal size , are mentioned, while .a Cotton- 

 wood (Populus monilifera) was eight feet in diameter and one 

 hundred and ninety feet in height. Thus it will be seen that 

 some of the Eastern deciduous trees almost rival the Pacific 

 Coast Conifers in size. Other giants of the eastern forest are 

 the White Pine, the Sycamore and Tulip tree. With these are 

 associated many shrubs and climbing plants, as well as a charac- 

 teristic flora composed of herbaceous plants, usually flowering in 

 the early spring before the leaves appear upon the trees. 



In the Mississippi Valley the forest is almost exclusively com- 

 posed of deciduous trees, but in the Appalachian forest there is 

 a mixture of coniferous trees, especially Pines and Hemlocks, 

 while in the north the proportion of these Conifers increases 

 and at the same time many of the deciduous trees disappear, and 

 the forest then consists of a comparatively small number of spe- 



