Capsicum, also known as Bell Pepper in NZ, is a cultivar group of the species Capsicum annuum. Cultivars of the plant produce fruits in different colors, including red, yellow, orange, green, chocolate/brown, vanilla/white, and purple.
Most typically, the unripe fruits are green. Some red, yellow, and orange peppers come from different seeds and are different cultivars of pepper. Some red peppers are simply ripened green peppers. Green peppers are less sweet and slightly bitterer than yellow or orange peppers, with red bell peppers being the sweetest. The taste of ripe peppers can also vary with growing conditions and post-harvest storage treatment; the sweetest are fruit allowed to ripen fully on the plant in full sunshine, while fruit harvested green and after-ripened in storage are less sweet.
Capsicum peppers are rich sources of antioxidants and vitamin C. Whilst the bell pepper is a member of the Capsicum genus, it is the only Capsicum that does not produce capsaicin, the chemical that can cause a strong burning sensation when it comes in contact with mucous membranes. The lack of capsaicin in bell peppers is due to a recessive form of a gene that eliminates capsaicin and, consequently, the "hot" taste usually associated with the rest of the Capsicum genus.