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
Ribes amarum to three flowers which hang from leaf axils. The showy flower has five pointed sepals in shades of purple-red which are reflexed upward. At the center is a tubular corolla of white or pink-tinged petals around five stamens and two styles. The fruit is a bristly berry up to 2 centimeters wide which is bright red, ripening purple. Ribes amarum Ribes amarum is a species of currant known by the common name bitter gooseberry. It is endemic to California, where it is known from mountains, foothills, and canyons. Its habitat includes Chaparral. "Ribes amarum" is a shrub growing to one