Several Hawaiian names are listed in the Manual - A'e, Hea'e, Manele or Kawa'u. I initially believed the Upper Waiakea plants shown below were Z. Kauaense. (The other option is z. hawaiiensis) They have grey-brown bark, and rather small leaves about 3-4 inches long that have a wonderful delicate lemon scent. The large trees I've found drop their leaves in July and flower in August. The endangered Z. Dipetalum looks quite different. It has grey bark and large dark green oval leaves, about 5-7 inches long.