Red chilies are the dried and ripened fruit of the Capsicum genus plant, also known as Capsicum annuum. They are hollow, with many seeds and pith that are the hottest parts. Red chilies are hot and pungent, with a smoky flavor profile and less floral or citrus notes than other varieties. They get their color from a compound called capsanthin, and their heat comes from capsaicin, a chemical that can irritate skin and eyes but also has medicinal benefits. The pungency of red chilies varies by variety and is measured on the Scoville scale.