Chili or chilli peppers are the fruits of plants from the Capsicum genus, which are members of the nightshade family, Solanaceae. They originated in Mexico (the name comes from the Nahuatl language which was used by the Aztecs), where they were domesticated more than 6000 years ago. They were one of the first self-pollinating crops to be cultivated in Mexico, Central and South America. Peru is considered to be the country with the highest cultivated Capsicum diversity because varieties of all five domesticated species were introduced, grown, and consumed there in pre-Columbian times. Spanish and Portuguese explorers and traders introduced chilis to Europe and Asia from the end of the 15th century. There are five main Capsicum species of cultivated chili peppers, and thousands of cultivars worldwide (some suggest up to 50,000). They are widely used in many cuisines, both fresh and dried forms and also in pastes and liquids.