The almond is the seed of the almond tree, Prunus dulcis. Almonds are eaten raw or toasted, ground into flour, or processed to produce almond milk, almond paste, or marzipan. In the Middle East, green almonds are eaten while sour as a snack food.
There are two main species of almond grown commercially. The bitter almond, which is closer to the wild type, has a bitter, inedible pit, which contains a high dose of hydrogen cyanide and can be lethal if ingested. The sweet almond has been bred for centuries to eliminate this acid, making the pit consumable by humans. The bitter almond is still grown because the pit is preferred for chemical extraction of almond flavor in almond extract and almond liqueurs.