Vicia nigricans is a species of vetch known by the common name black vetch. It has a disjunct distribution, its two subspecies divided by thousands of miles in range. The northern subspecies, ssp. gigantea (giant vetch), is native to western North America from Alaska to northern California, where it occurs in coastal and moist inland habitat and disturbed areas. The southern subspecies, ssp. nigricans, occurs in southern South America, in Argentina and Chile.