The macadamia tree is native to Australia and was first grown only for ornamental purposes... and then the great tasting nut was discovered. The tree was introduced to Hawaii (now one of the main producers of macadamia nuts) in the late 1800's and is found growing primarily in rain forests.
The macadamia nut itself is the seed that grows inside the hard woody shell of the fruit of the tree. The nuts fall to the ground between March and September each year and are harvested at regular intervals. The flavor of the macadamia nut is often compared to that of a superfine hazelnut.