162 BOTANICAL GAZETTE [MARCH 
pubescens, Anemone nemorosa, etc. Sometimes the bur oak ( Quer- 
cus macrocarpa) is the dominant tree in these morainic forests, 
though in such cases the habitat is usually more moist or else 
the drainage is less perfect. A bur oak forest is shown in Fig. 
29. The transition from this type to the morainic swamp for- 
ests, already mentioned, is an easy one, and bur oaks are often 



1G. 29.—Typical forest of low morainic clay soil, made up chiefly of bur oak 
(Quercus macrocarpa). 
found with the swamp white oak and other species characteristic 
of such places. , 
In spite of the abundance of the type of morainic forest 
described above, it is scarcely probable that it is anything more 
than a very slowly passing forest stage. The fact that in all 
directions from Chicago the ultimate forest type on morainic 
uplands is not the oak-hickory but the maple-beech forest leads 
us to expect that here. This latter type seems to be of a higher 
order in all respects. It is found in richer soil where the humus 
content is very great. Seedlings of the beech or maple can 
easily grow in the relatively light oak forest, whereas oaks cannot 
grow in the denser shade of the maple or beech. Furthermore, 

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