40 UNIVERSITY OF MISSOURI STUDIES [182 



in the region, of swamp and lowland oaks dominant in the up- 

 land plain. 



The bur oak {Quercus macrocarpa) prefers the heavier 

 soils, and occurs in the swamps and along the streams, though 

 it is properly a mesophytic tree. In the forest on the coal meas- 

 ures it is the most abundant oak, but with it there is common 

 the swamp oak (Q. platanoides) , though its natural home is the 

 swamp. The pin oak (Q. palustris) is, except in a few swamps 

 in the limestone district, restricted to the coal measures, where 

 it is a common and characteristic tree. 



The red oaks (Quercus Schneckii and Q. rubra) have a 

 wide distribution, but show a preference for either light or 

 heavy wet soil, and are rarest in the midland plain. The Texan 

 red oak (Q. Schneckii) is common also in park-like areas, re- 

 sembling in this respect the shingle oak (Q. imbricaria), which 

 is the commonest black oak as the sylva meets the prairie. 



The chestnut oak (Q. acuminata) is a common companion 

 of the white oak, but has a decided preference for rocky soils. 

 It is very characteristic of the cliffs and of rocky ravines. 

 The black oak (Q. tinctoria) is common in similar places, but is 

 the typical oak in dry oak forests, especially in light soils. The 

 forests south of the Pinnacles are good examples. The post 

 oak (Q. obtusiloba) and the black jack (Q. Marylandica) occur 

 only on the summits of the cliffs, and in the red clay barrens, 

 and are the representative xerophytic oaks. 



The following plants are characteristic of the sylva: 



a. Arbores. 



Juglans nigra C. tomentosa 



Carya alba C. porcina 



C. sulcata C. amara 



