Eutrema japonicum

Wasabi (Japanese: ワサビ, わさび, or 山葵, pronounced [waꜜsabi]) or Japanese horseradish (Eutrema japonicum syn. Wasabia japonica) is a plant of the family Brassicaceae, which also includes horseradish and mustard in other genera. The plant is native to Japan, the Russian Far East including Sakhalin, and the Korean Peninsula.: 133  It grows naturally along stream beds in mountain river valleys in Japan. Wasabi is grown for its rhizomes, which are ground into a paste as a pungent condiment for sushi and other foods. It is similar in taste to hot mustard or horseradish rather than chilli peppers, in that it stimulates the nose more than the tongue, but freshly grated wasabi has a subtly distinct flavour.: 53  The main cultivars in the marketplace are E. japonicum 'Daruma' and 'Mazuma', but there are many others. The oldest record of wasabi as a food dates to the 8th century AD. The popularity of wasabi in English-speaking countries has coincided with that of sushi, growing steadily from about 19......read more on Wikipedia.