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 in the unripe green berries, and immature fruit should be treated as toxic. Most cases of suspected poisoning are due to consumption of leaves or unripe fruit. There are ethnobotanical accounts of "S. nigrum" leaves and shoots being boiled as a vegetable with the cooking water being discarded and replaced several times to remove toxins. Some of the uses ascribed to "S. nigrum" in literature may actually apply to other black nightshade species within the same species complex, and proper species identification is essential for food and medicinal uses (See "Taxonomy" section). "S. nigrum" has been widely used as a