Milo fruit These are the fruit of the milo tree, or Thespesia populnea. Its wood is very popular for woodworking in Hawai'i, and the tree was at one time very abundant on Hawai'i.
This image is from the presentation "A Hawaiian Kaleidoscope - The Big Island: Volcanoes, Mauna Loa Climb, Heiaus and Beach Relaxation".