PRINCIPAL TREES. 
69 
not to be confounded with the true white birch (Betula populifolto) 
which does not seem to occur in this region and is a much inferior 
tree. The paper birch is the characteristic hardwood tree of the 
fresher sandy soils, is always small, grows best in the northern coun¬ 
ties, does not thrive on the poorer sandy “barrens,” occasionally 
forms small thickets, is generally mixed with pine and along Green 
Bay with arborvitae. Like aspen, it enters extensively in the brush 
cover of many cut-over bare lands, but thrives only where consider¬ 
able sand is present in the soil. 
3. ELM. 
a. White elm ( Ulmus americana ) is a tall, long-shafted tree common 
in all hardwood forests. 
b. Cork elm ( Ulmus racemosa ), commonly called rock elm, replaces 
to quite an extent the preceding species in many localities, and prob¬ 
ably forms near 30 per cent, of all elm of the region. 
A “bastard” elm, with the foliage of white elm and the bark of cork 
elm, is often noted by the woodsmen. 
c. Slippery elm ( Ulmus pubescens) occurs sparingly in parts of this 
region. 
4. MAPLE. 
a. Sugar maple ( Acer sacckarum ) is a common tree Of all hardwood 
forests, and, to a very considerable extent invades with aspen and 
paper birch the regular pinery. Among the small, young growth of 
most hardwood forests it predominates in number. 
b. Silver maple ( Acer saccharinum) , often called soft maple, is quite 
generally distributed throughout the mixed forest, as is also the 
Bed maple ( Acer rubrum). The bush maples, spiked and striped 
maple ( Acer spicatum and Acer pennsylvanicum ) form a considerable 
part of the undergrowth in the mixed woods of the clay land. 
5. OAK. 
a. Bed oak ( Quercus rubra) is the common timber oak of the region 
and occurs in all counties, and on both sandy and clay soils, but is 
abundant only in the western and southern counties, and makes a 
good tree only on the heavier soils. 
b. Wlrite oak ( Quercus alba) occurs quite abundantly in the south¬ 
ern and southwestern counties, but is very scarce, in any form, in 
the greater part of the region. This is also true of the 
c. Bur oak ( Quercus macrocarpa). In the north central and eastern 
parts, in the upper Wisconsin, Menominee and Peshtigo basins the 
scarlet oak ( Quercus coccinea) is generally the only “scrub oak”; it is 
scattered here over extensive tracts of sandy cut-over lands as a bushy 
