Coffee trees are shrubs or small trees, native to subtropical Africa and southern Asia. Seeds of several species are the source of the popular beverage coffee. After their outer hull is removed, the seeds are commonly called "beans". Coffee beans are widely cultivated in tropical and sub-tropical countries on plantations, for both local consumption and export to probably every other country in the world. Coffee ranks as one of the world's most valuable and widely traded commodity crops and is an important export of a number of countries.