Eutrema

Eutrema is a genus of flowering plants in the family Brassicaceae. It comprises herbaceous species native to temperate regions of Europe and Asia, with many species adapted to moist habitats such as stream banks, wetlands, and damp meadows. The genus includes plants commonly found in cool, shaded environments and often characterized by their winter-hardiness.

The best-known member is Eutrema japonicum, widely cultivated for its rhizome that is ground to produce the condiment known as wasabi. In some taxonomic treatments this plant is placed in the genus Wasabia (as Wasabia japonica), making Wasabi japonica a synonym of Eutrema japonicum. Other Eutrema species, such as Eutrema tenuissimum, are smaller and less intensively cultivated but occur in East Asia and surrounding regions.

Morphology typically includes herbaceous growth with simple leaves and small clusters of four-petaled flowers, a hallmark of many Brassicaceae. The fruit is a slender siliqua. Many species are perennial and some are adapted to fast-flowing or seasonally wet environments, reflecting their ecological affinity for moist conditions.

Taxonomy and relations: Eutrema belongs to Brassicaceae and is related to other genera such as Arabidopsis and Crambe. Taxonomic revisions have shifted some species between Eutrema and related genera, and names like Wasabia japonica have been used in horticultural and culinary contexts.

Uses and conservation: Eutrema japonicum is the principal species with significant culinary value due to wasabi production. Other species contribute to regional flora and may be used locally as leafy greens or ornamentals. Habitat loss and environmental changes threaten some wild Eutrema species, underscoring the need for habitat conservation.