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 bracteosum Ribes bracteosum Ribes bracteosum, the stink currant, is a species of currant native to western coastal North America from southeastern Alaska to Mendocino County in California. "Ribes bracteosum" is a deciduous shrub, without thorns, growing to 3 m (10 feet) tall. The leaves are 5–20 cm (2-8 inches) across, palmately lobed with 5 or 7 lobes. The flowers are produced in spring after the leaves emerge, on racemes 15–30 cm (6-12 inches) long containing 20-40 flowers; each flower is 5–10 mm (2-4 inches) in diameter, with five white or greenish-tinged petals. The fruit, born in clusters, is dark blue with