Our mystery "seeds" come from a tree that is only found in the southwestern U.S.
As a hint, it's common name relates to an animal. People think the bark resembles this particular animal's skin.
Do you have any ideas what the tree might be?
Edit: The answer is now posted. By the way, these are not really the seeds, but berry-like cones.
Note: We are quickly approaching our 100th Seed of the Week. To celebrate, I'd like to feature your favorite seed. Please send me the name of your favorite plant or seed and your first name to growingwithscience (at) gmail. com by January 19, 2012 and I'll create a list. If it is an unusual plant, please let me know a little about it, too.
Looking forward to hearing from you!