Meaning of sandbox tree

sand'box tree"

Pronunciation: [key]
  1. a tropical American tree, Hura crepitans, of the spurge family, bearing a furrowed, roundish fruit about the size of an orange that when ripe and dry bursts with a sharp report and scatters the seeds.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.