Wasabi (Japanese: わさび,ワサビ , 山葵 (originally written 和佐比); Wasabia japonica, Cochlearia wasabi, or Eutrema japonica) is a member of the Brassicaceae family, which inclues cabbages, horseradish and mustard. Known as "Japanese horseradish", its root is used as a spice and has an extremely strong flavor. Its hotness is more akin to that of a hot mustard than the capsaicin in a chili pepper, producing vapors that irritate the nasal passages more than the tongue. The plant grows naturally along stream beds in mountain river valleys in Japan. There are also other species used, such as W. koreana, and W. tetsuigi. The two main cultivars in the marketplace are W. japonica var. Daruma and Mazuma, but there are many others.