An important food and medicine! Peppers are second only to the tomato as a garden favorite. There are many varieties of spicy peppers varying greatly in heat. The level of heat in peppers is measured in 'Scoville Heat Units' - or SHU's - that represents the amount of Capsaicin present. Capsaicin is the chemical in peppers responsible for the stimulating, burning sensation when it comes in contact with mucous membranes and skin. Spicy peppers are an indispensable ingredient in Latin American and Asian cooking. Medicinally, the variety Cayenne is valued as a circulatory stimulant, for which it has no equal. Peppers are tropical perennials grown as annuals in temperate North America.