Hawaii Symbols, Tree: Kukui

Adopted in 1959.

A Polynesian introduced plant species. the kukui, better known as the candlenut. The nuts of this tree provided the ancient Hawaiians with light, oil, relishes, and medicine

Medium-sized tree, up to 20 m tall, ornamental, with widespreading or pendulous branches; leaves simple, variable in shape, young leaves large, up to 30 cm long, palmate, with 3–7 acuminate lobes, shining, while leaves on mature trees are ovate, entire, and acuminate, long-petioled, whitish above when young, becoming green with age, with rusty stellate pubescence beneath when young, and perisiting on veins and petiole; flowers in rusty-pubescent panicled cymes 10–15 cm long; petals 5, dingy white or creamy, oblong, up to 1.3 cm long; ovary 2-celled; fruit an indehiscent drupe, roundish, 5 cm or more in diameter, with thick rough hard shell making up 64–68% of fruit, difficult to separate from kernels; containing 1 or 2 seeds. Fl. Apr.–May (Sri Lanka).

Distribution: Native to Malaysia, Polynesia, Malay Peninsula, Philippines and South Seas Islands; now widely distributed in tropics. Naturalized or cultivated in Malagasy, Sri Lanka, southern India, Bangladesh, Brazil, West Indies, and Gulf Coast of United States

Uses: Seed yields 57–80% of inedible, semi-drying oil, liquid at ordinary temperatures, solidifying at -15°C, containing oleostearic acid. Oil, quicker drying than linseed oil, is used as a wood preservative, for varnishes and paint oil, as an illuminant, for soap making, waterproofing paper, rubber substitutes and insulating material. Seeds are moderately poisonous and press cake is used as fertilizer. Kernels when roasted and cooked are considered edible; may be strung as candlenuts. Oil is painted on bottoms of small crafts to protect against marine borers. Tung oil, applied to cotton bolls, stops boil weevils from eating them. Also prevents feeding by striped cucumber beetle.

Folk Medicine : 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 Sumatra, pounded seeds, burned with charcoal,are applied around the navel forcositiveness. 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 and to the pubes for gonnorhea

Source:
Purdue University. NewCROP