I finally decided to follow up on as clue that my cousin's son, Cory, provided to me. I wrote to Jill Martini, the Horticulture Manager of the Oregon Garden. She solved the mystery. Here is her response:
From your description it sounds like you are talking about a Clerodendrum trichotomum, common name: Harlequin Glorybower Tree or Peanut Butter Bush referring to its fragrance.
Thank you for your inquiry. Please come visit the garden soon.
The US Forest Service has an in interesting fact sheet on the tree. What you will not learn is that the tree is originally from eastern Asia -- principally, Japan. But it also appears that it would grow as a specimen tree in Mexico.
Special thanks to Cory and Ms. Martini for putting this 2008 mystery to rest. Like Miss Marple, we can all go home now, put up our feet, and have a nice cuppa.