Debi, When you say Hawaiian nut do you mean a Macadamia nut? They are too round.
We think we just found what we think is correct. From Google images we think it may be an Ohio Buckeye tree. Our pods are smooth but some of the pictures seem to be fairly smooth, although most are pretty spiky or spiny.
Thank you so much. You led us on a search which led to these photos.
If anyone else can help us confirm we welcome the help.
From: Debi Schmitt <email@example.com>
Sent: Friday, October 19, 2012 9:41 PM
Subject: [iris-photos] Help with mystery nut
I am pretty sure I have seen one of these before. I want to say Hawiian nut.
/ \\ debi
/ _.' /