Wasabi (Japanese: , , or , ; Eutrema japonicum or Wasabia japonica) or Japanese horseradish is a plant of the family Brassicaceae, which also includes horseradish and mustard in other genera. The plant is native to Japan and the Russian Far East including Sakhalin, also the Korean Peninsula. It grows naturally along stream beds in mountain river valleys in Japan. It 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 chili peppers in that it stimulates the nose more than the tongue, but freshly grated wasabi has a subtly distinct flavor. The two 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 starting in about 1980. Due to issues that limit the Japanese wasabi plant's mass cultivation and thus increase its price and decreased availability outside Japan, the western horseradish plant is generally used in place of the Japanese horseradish. This version is commonly referred to as "western wasabi" () in Japan. Taxonomy Siebold named Cochlearia (?) wasabi in 1830, noting its use pro condimento or "as a condiment"; however, this is a nomen nudum, and the synonym Eutrema wasabi, published by Maximovich in 1873, is thus an illegitimate name. The wasabi plant was first described by Miquel in 1866, as Lunaria (?) japonica, from the type collected by Siebold in Japan, though the precise type locality was not recorded. In 1899, Matsumura erected the genus Wasabia, recognizing within it the species Wasabia pungens and Wasabia hederaefolia; these are now regarded as synonyms of Eutrema japonicum. In 1912, Matsumura recognized the species Wasabia japonica, treating his earlier Wasabia pungens as a synonym. In 1930, Koidzumi transferred the wasabi plant to the genus Eutrema, the correct name and author citation being Eutrema japonicum (Miq.) Koidz. Description It has large leaves produced from long, thin stalks. They are simple and large, long and wide with palmate veins. Wasabi flowers appear in clusters from long stems that bloom from late winter to early spring. Uses Wasabi is generally sold either as a rhizome or stem, which must be very finely grated before use, as