Blackcurrant can damage both unopened and open flowers when the temperature falls below . The flowers at the base of the strig are more protected by the foliage and are less likely to be damaged. In midsummer the strigs of green fruit ripen to edible berries, very dark purple in colour, almost black, with glossy skins and persistent calyxes at the apex, each containing many seeds. An established bush can produce about 4.5 kilograms (10 pounds) of fruit each year. Plants from Northern Asia are sometimes distinguished as a separate variety, "Ribes nigrum" var. "sibiricum", of which "Ribes cyathiforme" is considered
Solanum nigrum to make 16-DPA progenitor); a possible commercial source could be via cultivating the hairy roots of this plant. Black nightshade is cultivated as a food crop on several continents, including Africa and North America. The leaves of cultivated strains are eaten after cooking. A garden form with fruit diam. is occasionally cultivated. Black nightshade can be a serious agricultural weed when it competes with crops. It has been reported as a weed in 61 countries and 37 crops. Herbicides are used extensively to control it in field crops such as cotton. Solanum nigrum Solanum nigrum (European black nightshade) is a