Chocolate is made from cocoa beans, the dried and partially fermented seeds of the cacao tree (Theobroma cacao), a small (4– to 8-m-tall (15– to 26-ft-tall) evergreen tree native to the deep tropical region of the Americas. Recent genetic studies suggest the most common genotype of the plant originated in the Amazon basin and was gradually transported by humans throughout South and Central America. Early forms of another genotype have also been found in what is now Venezuela. The scientific name, Theobroma, means "food of the deities".[42] The fruit, called a cacao pod, is ovoid, 15–30 cm (or 6–12 in) long and 8–10 cm (3–4 in) wide, ripening yellow to orange, and weighing about 500 g (1 lb) when ripe.
Cacao trees are small, understory trees that need rich, well-drained soils. They naturally grow within 20° of either side of the equator because they need about 2000 mm of rainfall a year, and temperatures in the range of 21 to 32°C. Cacao trees cannot tolerate a temperature lower than 15°C (59°F).[43]
The three main varieties of cacao beans used in chocolate are criollo, forastero, and trinitario.