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 roezlii Ribes roezlii Ribes roezlii is a North American species of currant known by the common name Sierra gooseberry. "Ribes roezlii" is native to many of the mountain ranges of California, its distribution extending east into Nevada and north into Oregon. Its habitat includes chaparral, woodlands, and forested areas. "Ribes roezlii" is a spiny shrub growing erect to a maximum height around . The hairless to hairy or woolly leaves are up to 2.5 centimeters (1 inch) long and divided into 3 or 5 rounded, toothed lobes. The inflorescence is a solitary flower or raceme of 2 or 3 small wind-pollinated