Kukui Nut is a medium to large sized tree with widespreading or pendulous branches. Young leaves are large, up to 12" long. Palmate, shiny leaves on mature trees are ovate, entire, and acuminate. There is a whitish substance above them when young, that becomes green with age, with rusty stellate pubescence beneath when young, and perisiting on veins. Small flowers in rusty-pubescent panicled cymes, dingy white or creamy. Fruit an indehiscent drupe, roundish, 2" or more in diameter. Bears two heavy crops each year, harvested when mature.
The kukui nut has many uses. Originally it was most valued for its light, the oil of the white kernels being extracted for its use in stone lamps and in ti leaf sheath torches. The tree is sometimes called the Candlenut Tree. The nuts are widely used as a traditional lei, both the hard shells of the polished black, tan or brown, and immature white, which are more rare. The Kukui Nut lei were worn by royalty back in the days of the Hawaiian monarchy (Alii). The kukui nut leis are finished and polished and will last for years. The bark, flowers and nuts are all used for medicine. As food, a small amount of the pounded roasted nuts, plus salt and sometimes chili peppers, is used as a relish and is called inamona. Pure Kukui Nut Oil has been used by Hawaiians for centuries to protect and heal skin exposed to harsh sun, drying winds, and salt water. Kukui Nut Oil penetrates the skin well and is said to be excellent in treating many skin conditions including psoriasis, eczema, aging skin, and acne. Bark used on tumors in Japan. The oil is purgative and sometimes used like castor oil. Kernels are laxative stimulant, and sudorific. The irritant oil is rubbed on scalp as a hair stimulant. In Malaya, the pulped kernel enters poultices for headache, fevers, ulcers, and swollen joints. In Java, the bark is used for bloody diarrhea or dysentery. Bark juice with coconut milk is used for sprue. Malayans apply boiled leaves to the temples for headache.