The “hot” in hot peppers is due to capsaicin (C18H27NO3), a colorless, odorless oil-like compound found in the fruit of a plant that is a close relative of the tomato. Capsaicin is primarily found in the membrane that holds the seeds. These plants are found in the Americas and were brought to Europe by explorer Christopher Columbus who mistakenly thought they were a relative of the black pepper (the plant we get pepper from). To distinguish them from the black pepper plant, hot peppers are usually called chili peppers, or just plain chilis in many parts of the world. Capsaicin is also found, in smaller amounts, in other spices, such as oregano, cinnamon, and cilantro.