38 THE VEGETATION OF THE UNITED STATES. 



In the northern part of the Transition belt the commonest trees are 

 black oak {Quercus velutina) and bur oak (Q. macrocarpa); in the 

 southern part the commonest are post oak (Quercus minor) and 

 blackjack (Q. marilandica) . The grasses originally most abundant in 

 the central part of the belt were Andropogon furcatus, Sorghastrum 

 nutans, Andropogon virginicus, and Sporobolus cryptandrus. 



Deciduous Forest. — The Deciduous Forest formerly occupied the 

 lower elevations of the Northeastern States, the summits and slopes 

 of the southern Allegheny Mountains, the Piedmont region, and the 

 valleys of the Ohio, Cumberland, and Tennessee Rivers, with exten- 

 sions into southern Texas and into northern Michigan and the Dakotas, 

 and an attenuated edge that merges into the transition area toward 

 the west. There is no one of the vegetational areas of the United 

 States that has been more completely and profoundly altered by man 

 than has this one. In fact, it is difficult at the present time to secure 

 reliable information as to the exact original extent of this type of forest 

 in the Northeastern States. The virgin stands of deciduous forest were 

 made up solely of deciduous broad-leaved trees over extensive areas, 

 and these forests were both dense and of a stature as great as 100 feet, 

 or even more. At the western edge of the Deciduous Forest its con- 

 tinuity becomes interrupted by open areas, while in the Texan exten- 

 sion of it the stand of trees is even, but very open. In all of the moun- 

 tainous or hilly portions of the area the needle-leaved evergreens 

 frequently become components of the Deciduous Forest, and on steep 

 bluffs, rocky slopes, and limestone ledges the needle-leaved trees are 

 sometimes predominant. The floor of the Deciduous Forest is some- 

 times thickly covered with shrubbery and young trees, or is often open 

 and more conspicuously occupied by herbaceous perennials, among 

 which the chief vegetative activity takes place in the spring, before 

 the complete unfolding of the foliage of the trees. 



The number of tree species participating prominently in the make-up 

 of the Deciduous Forest is large, and very many of the commonest 

 ones are found almost throughout the area, as the white oak {Quercus 

 alba), black oak {Quercus velutina), pignut hickory {Hicoria glabra), 

 beech {Fogus ferruginea), and tulip-tree {Liriodendron tulipifera). 

 The Appalachian region is the place in which the Deciduous Forest 

 reaches its finest development, both in respect of density and stature 

 of the stand and with regard to the number of tree species participat- 

 ing in its composition. The most common trees of that region are the 

 widespread ones which have just been mentioned, and also chestnut 

 {Castanea dentata) , chestnut oak {Quercus prinus) , scarlet oak {Quercus 

 coccinea), shagbark hickory {Hicoria ovata), Spanish oak {Quercus 

 digitata), sugar maple {Acer saccharum), and red maple {Acer rubrum). 

 On passing northward from the center of the Deciduous Forest, the 

 number of tree species becomes smaller, as many are left behind and 



