Cayenne pepper. Ground, hot red chillis. They are tapered and contain twice as much capsaicin as red peppers, which is why they provide so much heat to food. Chillis are often available in dried or powdered forms. Colour is not necessarily a guide to the heat, which is measured in Scoville units (named after Wilbur Scoville). Generally speaking the scale goes from small and pointed, with thin skins, having the most heat through to large and blunt having the least. The greatest heat is contained in the membranes and seeds.