山葵 (wasabi) is a green condiment commonly used in Japanese cuisine, particularly with sushi and sashimi. It has a strong, pungent flavor that can create a spicy sensation in the nose rather than on the tongue. The plant, known scientifically as Wasabia japonica, grows in cool, running water and is native to Japan. The root of the wasabi plant is grated to produce the paste or powder used in dishes. Authentic wasabi is often expensive and can be difficult to find outside of Japan, leading many to use substitutes made from horseradish and food coloring.