BLACK WALNUT: ITS GKOWTH AND MANAGEMENT. 
17 
of the forest canopy. 
The greater merchant- 
able length, the more 
slender and more grad- 
ually tapering stems, and 
the smaller, more re- 
stricted' crowns of forest- 
grown trees are in con- 
spicuous contrast to the short, thick, rapidly 
tapering trunks and full crown of trees 
grown in the open. Of two neighboring 
trees measured in Indiana — one a field and 
the other a forest tree — the former, because 
of rapid taper and low branches, had only 
about 15 feet of merchantable length, but 
the latter had nearly 30 feet. Forest-grown 
trees near Fort Wayne, which measured from 
30 to 35 inches in diameter, breast high, had 
from 64 to 72 feet of merchantable length. 
It is very characteristic of walnut, both in 
the open and in the forest, for the main trunk 
to break up within a few feet of the lowest 
limbs into a number of large branches, no one 
of which appears to be the leader. 
TWIGS. 
A characteristic feature of the twigs, by 
which black walnut and butternut may be dis- 
tinguished from other trees, is the way in 
which the pith is divided by thin diaphragms 
into spaces or chambers. The pith of black 
walnut is of a pale buff color, but that of but- 
ternut is dark brown. 
ROOTS. 
The root system of black walnut is deep 
seated and characterized by a marked tap- 
root. This is well defined even during the 
first year of the seedling. Later the tree 
throws out prominent lateral roots. 
BARK. 
The bark of black walnut is one of the most 
variable features of the tree, the differences 
being caused largely by different rates of 
19340°— 21 3 
Fig. 4. — Black walnut seed- 
ling from a brushy site, 
at beginning of third 
year of growth. 
