Bitter vetch is a common name for several plants and may refer to:Vicia ervilia, called bitter vetch or ervil, an ancient grain legume crop of the Mediterranean region. Vicia orobus, called wood-bitter vetch, a legume found in Atlantic areas of Europe. Lathyrus linifolius, called bitter vetch or heath pea, a species of pea. Lathyrus niger, called black bitter vetch or black pea, a perennial legume native to Europe.