Some of the more unusual varieties have been kohlrabi, peanuts, and orach.
British Dictionary definitions for orach
any of several herbaceous plants or small shrubs of the chenopodiaceous genus Atriplex, esp A. hortensis (garden orache), which is cultivated as a vegetable. They have typically greyish-green lobed leaves and inconspicuous flowers
C15: from Old French arache, from Latin atriplex, from Greek atraphaxus, of obscure origin