The areca nut is the seed of the areca palm (Areca catechu), which grows in much of the tropical Pacific (Melanesiaand Micronesia), Southeast and South Asia, and parts of east Africa. This seed is commonly referred to as betel nut so it is easily confused with betel (Piper betle) leaves that are often used to wrap it (paan). The term areca originated from a South Asian word, Malayalam: Adakka during the 16th century, when Dutch and Portuguese sailors took the nut from Kerala to Europe. Consumption has many harmful effects on health and is carcinogenic to humans. Various compounds present in the nut, most importantly arecoline (the primary psychoactive ingredient which is similar to nicotine), contribute to histologic changes in the oral mucosa. As with chewing tobacco, its use is discouraged by preventive efforts. The areca nut is not a true nut, but rather a fruit categorized as a berry. It is commercially available in dried, cured and fresh forms. When the husk of the fresh fruit is green, the nut inside is soft enough to be cut with a typical knife. In the ripe fruit, the husk becomes yellow or orange and, as it dries, the fruit inside hardens to a wood-like consistency. At that stage, the areca nut can only be sliced using a special scissors-like cutter.