Betel nuts, the fruit of the Areca catechu palm tree, also known as the Betel Palm, contain the stimulant arecoline. Native to SE Asia, the ground nuts are often combined with mineral lime and wrapped in the leaf of a Betel pepper plant, although they are sometimes consumed buccally ('chewed') alone. Notably, frequent use can stain teeth black and its daily use is associated with increased risk of mouth cancers. Variants of the betel and lime combination are extremely common in many Asian cultures and have a long history of human use.