Wasabi is the hot and stimulating green paste that lends a characteristic, pungent taste to sushi dishes, dressings and dipping sauces. The wasabi plant, sometimes called Japanese horseradish, has long been used in Japan as an essential condiment for serving with sushi, soba and tofu and more recently to flavour dressings, dips and snacks. Wasabi is a member of the Brassicaceae family which include cabbages, horseradish and mustard. It is the stem and not the root which is used to make the condiment wasabi. It has been cultivated in Japan since the 16th Century and it grows naturally along shaded riverbeds in mountain valleys in Japan. It takes two years to mature and is very perishable.