|images courtesy Steve Goebel Jr|
"Striking tree or more often large shrub, virtually unknown in commerce and gardens, zones 5-8, introduced via the Plant Select program at Colorado State University." Roasted seeds reportedly taste a little like macadamia nuts. In the mostly tropical Sapindaceae family, which now includes maples and horse-chestnuts.
Methinks the big payoff is the flower. Never seen it, but I've got to have one.
Image is ripped from the