any of a genus (Atriplex) of plants of the goosefoot family, widespread in salty or alkaline areas, having usually silvery foliage and small green flowers; esp., (A. hortensis), cultivated as a potherb, chiefly in France
See orach in American Heritage Dictionary 4
also or·ache(ôrˈĭch, ŏrˈ-)
noun
Any of various plants of the genus Atriplex, especially A. hortensis, having edible, spinachlike leaves.