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 marshallii lobes. Glandular hairs occur on veins and leaf margins. The inflorescence is a solitary flower or raceme of up to three flowers which hang pendent from the branches from leaf axils. The small, showy flower has five pointed purple-red sepals which are reflexed upward. At the center is a tubular corolla of bright yellow petals from which emerge five stamens and two thin, mostly fused styles. The fruit is a prickly oblong berry up to 2 centimeters (0.8 inch) long which ripens to dark red. The fruits are edible and reputedly palatable. Ribes marshallii Ribes marshallii is a North American