As determined by extensive molecular studies and critical evaluation of morphology, the genera Eutrema, Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella form a monophyletic assemblage treated here as one genus under the oldest name, Eutrema. The present synopsis of Eutrema includes a listing of all 26 species presently assigned to the genus, including 14 new combinations (E. altaicum, E. botschantzevii, E. fontanum, E. fontanum subsp. microspermum, E. grandiflorum, E. halophilum, E. lowndesii, E. parvulum, E. platypetalum, E. salsugineum, E. verticillatum, E. violifolium, E. wuchengyii, and E. yungshunensis) and 3 new names (E. hookeri, E. schulzii, and E. sherriffii). It also includes a detailed description of the combined genus, distributions, and a key to all species.