Hickory Challenge : Which Species?

The hickory is just slightly outside the neighborhood, at L'Hirondelle , corner of the driveway leading into the old Rugby field.  There are a couple of reasons to add the hickory.  First there are probably some hickories closer along Towson run, just hard to get close.  Second, it is an important tree historically and the local forest were known as hickory forests  along with the oaks, beech, and maples.  With the diverse mix of neighborhood trees there should be more hickories.

The divided nut, the alternate leaves, pinnate with an odd leaflet at the end is consistent with hickory. It is just not clear to me which variety.  There are more than five relatively narrow leaflets.  But the leaflet margin is serrated.  It doesn't seem to fit the common groups.  There could be hybridization or it could be a simple category overlooked.  The twig I have is too small to see the star shaped pith but the pith seems solid.

A final reason for showing the hickory relates to the hundred year old pecan tree on Maple Ave.  It produces copious quantities of nuts and would tend not to be self-fertilizing .  If there are no other pecans in the area, it might be possible for the local hickories to pollenate the pecan.  Producing one of the Hican hybrids in the nuts.

Shown is a small branch with three leaves and a transillumination to show the leaf margin.  Extra credit if you can explain the slightly orange vertical background artifact.  It is an interaction between the fluorescent lightbox and the cellphone camera.  It orients with the light box.

Update: So there has already been an inquiry about the terminal buds.  This is shown in the last photo and yes in seems to have a sulfurous yellow quality.  I naturalist first suggestion was pecan, which was interesting.  The terminal bud helps with that.

Alternate,oddly pinnate leaves with 9 leaflets and divided  small fruit.

Margin is serrated not entire,veins end in point. Stripes are  camera artifact.

terminal bud from the mystery hickory.