山葵（日语：山葵／わさび／ワサビ），学名Eutrema japonica，是一种属于十字花科山萮菜属的植物，又称为「山嵛菜」，为绿色植物，味道极其强烈。它的辛辣跟辣椒不同，辣椒的辣味刺激舌头，而山葵的辣味却刺激鼻窦。山葵常见于日本山谷河流旁边生长，其他品种包括 W. koreana 及 W. tetsuigi；市面上普遍出售的两种山葵是 W. japonica 'Daruma'（达磨） 及 W. japonica 'Mazuma'（真妻），但山葵还有许多不同品种。

Wasabi(わさび（山葵）, earlier 和佐比; Eutrema japonicum/"Wasabia japonica") is a plant of the Brassicaceae family, which includes cabbages, horseradish, and mustard. It is also called Japanese horseradish, although horseradish is a different plant (which is generally used as a substitute for wasabi, due to the scarcity of the wasabi plant). Its stem is used as a condiment and has an extremely strong pungency more akin to hot mustard than the capsaicin in a chili pepper, producing vapours that stimulate the nasal passages more than the tongue. The plant grows naturally along stream beds in mountain river valleys in Japan. The two main cultivars in the marketplace are E. japonicum 'Daruma' and 'Mazuma', but there are many others. The origin of wasabi cuisine has been clarified from the oldest historical records; it takes its rise in Nara prefecture.