Vaccinium macrocarpon, the cranberry or large cranberry (sometimes classified in the genus Oyycoccos), is a dwarf, prostrate, mat-forming, evergreen shrub species in the Ericaceae (heath family) native to North America and typically found in bog mats, although it may grown in other wet areas (including dune swales and nutrient-poor fens). This species is the source of all commercially cultivated cranberries, although the small or European cranberry (V. oxycoccos, which occurs in northern Europe and northern Asia, as well as North America) is also wild-harvested and commonly used in Europe. Cranberries, which are high in vitamin C and iron, are popular for making into juice, as well as for use in cranberry sauce, jellies, and jams. Cranberries are also sold in supplement form for their beneficial effects on the urinary tract.

Cranberries are creeping woody plants with slender stems up to 1 m (3 ft) long and alternate, elliptic to oblong evergreen leaves up to 2 cm (0.75 in) long, with obtuse points at the leaf tips (or they may be rounded or even slightly notched at the tips) and white beneath. The pink campanulate (bell-shaped), 4-parted flowers are borne in lateral clusters of several flowers each. The fruits are berries that ripen to bright red, and are around 2 cm in diameter, considerably larger than in V. oxycoccos, which has fruit less than 1 cm (3/8 in) across. When cultivated commercially, the plants are often grown in sandy marshes, which are floody at harvest time, allowing the ripe fruits to float to the top, where they can be scooped up by mechanical harvesters.

Cranberry species, which have a more limited distribution than various other North American Vaccinium species, are an important seasonal food source for several species of birds. They were an important food for native peoples of North America for many centuries, but were generally wild-harvested, sometimes in managed stands, rather than cultivated. The development of cultivated varieties cranberries occurred only during the past 100 years, making it one of the most recently domesticated fruit crops.

FAO estimates that the total commercial harvest of cranberries was 394,606 metric tons in 2010, harvested from 22,444 hectares. The U.S. was responsible for 78% of the total, and Canada produced 19%, with considerably smaller harvests in Belarus, Azerbaijan, and Latvia, among others. Within the U.S., Wisconsin and Massachusetts are the leading cranberry producers, responsible for 58% and 28%, respectively, of the U.S. harvest, followed by New Jersey, Oregon, and Washington. These figures likely understate the full economic importance, as many fruits are wild-harvested for local, rather than commercial use.

(Bailey et al. 1976, FAOSTAT 2012, Flora of North America 2012, Hedrick 1919, Martin et al. 1951, NASS 2011, van Wyk 2005.)