20250710

These are photos of what look like borer entry holes in a
feral California black walnut. The tree was sprouted from
seeds collected in Davis, CA in about 2010. The tree is
unusual in two respects compared to other seedlings from
that group:

This particular tree has grown about twice as fast as
the other half-dozen in the group, given similar conditions.

The bark is a much lighter shade of grey with a much smoother
surface. Very clearly a different sort of plant. 

Black walnuts are common as ornamentals and Persion walnuts
are a major commercial crop, so it's likely a cross of some
sort. This crossing has been going on for close to two centuries,
so it's a little surprising that only one of the six trees
in the group is so different.