macadamia, name for the nut of the Macadamia ternifolia, an evergreen tree native to Australia, but cultivated in Hawaii. The nuts, also called Queensland nuts, are eaten roasted or raw. The macadamia tree is classified in the phylum Magnoliophyta, class Magnoliopsida, order Proteales, family Proteaceae.

Any of about 10 species of ornamental evergreen trees, in the family Proteaceae, and their edible, richly flavoured dessert nuts. Macadamias originated in the coastal rainforests and scrubs of northeastern Australia. Those grown commercially in Hawaii and Australia are principally of two species, the smooth-shelled Macadamia integrifolia and the rough-shelled M. tetraphylla. Macadamias are grown in quantity also in parts of Africa and South and Central America. Hard to propagate and slow to bear fruit, the trees grow only in rich, well-drained soil in areas receiving 50 in. (130 cm) of rain annually. Fragrant pink or white flower clusters on trees with large, shiny, leathery leaves produce bunches of 1–20 fruits. The nuts contain much fat but are a good source of minerals and vitamin B.

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