Ribes nigrum, black currant or European black currant, is a deciduous low-growing shrub in the Grossulariaceae (currant and gooseberry genus, although in many classifications formerly included in Saxifragaceae), native to northern Europe and northern Asia, which is widely cultivated for its fruit both commercially and in home gardens. Cultivated varieties of black currant that have been developed over the past several centuries are hybrids of several Eurasian species that were later crossed with North American species including R. bracteosum (California or stink black currant, which is generally considered to have a disagreeable flavor) and R. petiolare (western black currant). R. americanum, also known as black currant, is a wild species native to North America.
Blackcurrants should not be confused with “Zante currants,” a widely sold dried fruit, which are actually from a seedless cultivar of the grape species, Vitis vinifera.
Ribes nigrum is a many-branched shrub that generally grows to 1 to 2 m (3 to 6.5 ft) in height, with pubescent (hairy) to smooth stems, lacking the spines or prickles that are common on many Ribes species. The leaves are alternate and simple, with 3 to 5 coarsely toothed lobes; the terminal lobe is longer than the side lobes. The small bisexual flowers, greenish yellow to pinkish, are borne in long arching racemes (clusters). The flowers are somewhat campanulate, with 5 petals at the end. The smooth-skinned, globe-shaped fruit, which ripens to dark purplish black, is a juicy berry (a soft fleshy fruit with several to many soft seeds embedded in the pulp), with the remains of the calyx (flowering parts) persisting at the end.
The sweet, somewhat tart and acidic fruits, which are very high in vitamin C, are rarely sold fresh, but are generally prepared into jams, jellies, and juices, and used in a wide variety of baked goods and desserts, or served as an accompaniment to meat dishes. They are most typical in European cuisine. Blackcurrants are used to make the popular liqueur, crème de cassis. Blackcurrants are often included in natural supplements promoted for their immune-boosting properties during cold and flu season. The seeds contain alpha- and gamma-linoleic acids, which recent research has found can offer moderate immune system enhancements.
The U.N. Food and Agriculture Organization (FAO) estimates that 2010 commercial production of all species of currants (both black and red) was 640,968 metric tons harvested from 119,529 hectares in the Northern Hemisphere. The Russian Federation was the leading producer, alone responsible for 51% of the crop, with Poland contributing another 30%. Other countries that produced more than 1.5% of the total were Ukraine, Austria, United Kingdom, Germany, and Denmark.
Ribes nigrum has naturalized in parts of North America and China after cultivation, although it is not generally considered an aggressive invader. Planting of this and other Ribes species was restricted in many northern U.S. states during the 1930s through 1950s, after it was discovered that Ribes species were an alternate host for white pine blister rust, Cronartium ribicola, a fungal disease that affects the commercially important white pine, Pinus strobus. Regulations prohibit planting of currants within a specified distance from pine stands. Although studies conducted in national forests in the 1960s suggested that removing Ribes made no difference in the incidence of the blister rust in pine stands, Ribes remains listed as a noxious weed in Michigan and is restricted in Maine.
(Bailey et al. 1976, Carlson 1978, Flora of China 2003, Michigan Flora Online 2011, USDA PLANTS 2012, van Wyk 2005, Wu et al. 1999.)