Eutremananum, a new high-elevation (4500-4600 m) species from Chola Shan, Sichuan (Southwest China), is described and illustrated. It is similar morphologically to E.nepalense but is readily distinguished by having oblong to elliptic or obovate to spatulate (vs. suborbicular to broadly ovate) leaves, glabrous (vs. puberulent) sepals and ovate to oblong fruit 4-7 × 2-3 mm with flattened valves (vs. ovoid to subglobose fruit 2-3 × 1.8-2 mm with rounded valves). The genetic differences amongst E.nanum, E.nepalense and other close relatives are further confirmed by phylogenetic analyses using ITS and cpDNA sequence variations. The new combination E.sinense is proposed.
Keywords: Cruciferae; Eutrema nanum; Eutrema sinense; Sichuan; molecular phylogeny.