As hard as it is to believe, the macadamia tree was first grown only for ornamental purposes. Thankfully, the buttery-rich, slightly sweet nature of the tree's nut was eventually discovered and has been prized ever since. The macadamia tree is native to Australia and was named for John McAdam, the Scottish-born chemist who cultivated it. In the 1890s the macadamia journeyed from Tasmania to be cultivated in Hawaii (now its largest exporter) and, eventually, California. Because of its extremely hard shell, this marble-size, golden brown nut is usually sold shelled, either roasted or raw. It has a high fat content and should be stored in the refrigerator or freezer to prevent rancidity. Macadamias are widely used in a variety of sweet and savory dishes.