Without seeing the plant, my guess is Monkeypod or Albizia. Both are in the mimosa family, leaves fold at night. Both are beautiful. Monkeypod is a popular landscaping tree in Hawaii, Albizia a giant invasive monster.

believe it or not, i also brought back what sounds like the same seed two years ago. came from the makena area of maui. plant is now approx. 30" tall. no one hear has been able to identify it but it acts like a mimosa. i'll see if i can load a picture later. don