A recently domesticated native North American fruit crop, the American cranberry, Vaccinium macrocarpon, is a diploid member of the Vaccinium genus of the acid-loving Ericaceae. The morphology and chemistry of the fruit are unique in contrast to other fruits. Fruit have hollow locules, contain benzoic acid, and are high in polyphenolic antioxidants, including unique A-type proanthocyanidins, which are beneficial to human health. Moreover, instead of fruity volatiles found in other fruit species, the major volatile is 1-ɑ terpineol. Relative to other crop species cranberry has undergone relatively little genetic improvement. Major breeding objectives are fruit rot resistance, heat stress tolerance and enhancement of phytochemical constituents.