Wasabi (わさび(山葵)?, originally 和佐比; Eutrema japonicum),[1] is a plant, member of the Brassicaceae family, which includes cabbages, horseradish, and mustard. It is also called Japanese horseradish,[2] although horseradish is a different plant (which is often used as a substitute for wasabi). Its stem is used as a condiment and has an extremely strong pungency. Its hotness is more akin to that of a hot mustard than that of the capsaicin in a chili pepper, producing vapours that stimulate the nasal passages more than the tongue. The plant grows naturally along stream beds in mountain river valleys in Japan. The two main cultivars in the marketplace are E. japonicum 'Daruma' and 'Mazuma', but there are many others.[3]