This medium-sized tree grows along the library side of the sidewalk near the corner of the older part of the central library building. It is near where the sidewalk from Frist and Godchaux Halls meet the sidewalk along the side of the library.
Black walnut leaves
are one of the largest singly pinnate (leaflets arranged along a single central rachis) leaves in this area. Trees with similar leaves are tree of heaven
. Later on this tour you will have an opportunity to compare another walnut tree with a tree of heaven nearby. The leaflets of tree of heaven have a distinctive gland
in a notch at the base of each leaflet. Walnut leaflets
do not have this gland. Walnut twigs
also have unusual chambered pith (please do not cut branches or twigs from trees on the Vanderbilt campus) and tree of heaven twigs do not. This large walnut tree shows the distinctive furrowed bark
of walnut, which is quite different from the smoother bark of tree of heaven
. Pecan trees are not common in the wild in this area so they aren't likely to be confused with walnut there. Pecan bark
is also not deeply furrowed and its twigs do not have chambered pith.
If the fruits are present, these three trees can't be confused. Walnuts
are very hard, round, and surrounded by a thick husk that doesn't split along any particular lines. In the fall, this particular tree usually has fruits hanging on the branches at eye level or on the ground beneath it. Pecans
are oblong with a thinner shell and when ripe, their husks splits fairly easily into several pieces. Tree of heaven fruits
are not nuts but rather are thin and winged.
Black walnut trees are fairly common in forests in this area, although large trees are somewhat rare because they are frequently cut for their valuable wood.