If you love sushi and relish the wasabi (ワサビ)（山葵), take note. Wasabi, otherwise known as Japanese horseradish is a plant that grows naturally along stream beds in mountain river valleys in Japan and its root (inset) is used to make the light green and extremely hot condiment that vapourises to stimulate your nasal passages. It is sad to note though that real wasabi is said to be expensive and the one served nowadays may be made from special wasabi powder which contain not just flavoring and coloring but high levels of metals as well; the latter when taken for long term could lead to liver and kidney damages.The fake wasabi is bright green and has a very strong pungent smell that will dissipate in half an hour. A drop of iodine on the fake wasabi may render it blue within one to two minutes. You would want to check that out the next time you have your wasabi!