The plant genus was discovered in the 19th century by the then director of the Melbourne Botanic Garden on one of his many expeditions; he named it after his friend John McAdam. Macadamia trees grow up to 15 feet tall. About a dozen spherical, green fruits each ripen on pendulous flower panicles; when they burst open, the nuts fall to the ground. Macadamia nuts in the trade mostly come from the species M. integrifolia and M. tetraphylla and their crosses.

The "queen of nuts" originates from the rainforests of Australia and, along with the eucalyptus, is the only plant of commercial importance that comes from this part of the world. Today, macadamias are also grown in the subtropical and humid climates of Hawaii, New Zealand and South Africa, among others. By pressing the carefully dried nut kernel, an oil with a delicate nutty fragrance is obtained. But before one can get to the nut kernel, the extremely hard shell of the macadamia nuts must be overcome. Human strength is not enough; rotating steel cylinders usually do the cracking.

With up to 78 percent oil, the macadamia nut is as rich in fat as otherwise only the pecan nut. Macadamia oil consists mainly of unsaturated fatty acids, one of which is palmitoleic acid. While its content in plants is almost always less than one percent, macadamia oil contains almost 20 percent of this extremely skin-friendly fatty acid. Palmitoleic acid ensures that macadamia oil spreads excellently and is absorbed particularly well into the skin. Overall, macadamia oil is very well tolerated, but due to the complex extraction process, it is expensive and is rarely used in its pure form.