- The fruit of the annual bush, Capsicum annuum Longum Group, related to the sweet pepper but thinner and up to 9 cm long. They mature from green to red becoming hotter as they mature. The main sources of the capsaicin and other hot-flavouring compounds are the seeds and internal white pith which can be discarded. They are used for flavouring and as an appetizer. If eaten raw or cooked they can be intensely irritating to the mucous membranes unless the person is habituated to them, and hands should be thoroughly washed after handling. Much used in Indian, Mexican and other highly spiced cuisines. See under individual names, anaheim chilli, banana chilli, chilli arbol, chilli California, chilli cascabel, chilli pequin, chilli poblano, Fresno chilli, guajillo, guero chilli, habanero chilli, jalapeno chilli, New Mexico chilli, serrano chilli, etc.