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 varieties and forms described. The recognized subspecies are: 1. "S. nigrum" L. subsp. "nigrum" — glabrous to slightly hairy with appressed non-glandular hairs 2. "S. nigrum" L. subsp. "schultesii" (Opiz) Wessley — densely hairy with patent, glandular hairs The Solanum nigrum" complex — also known as Solanum" L. section "Solanum" — is the group of black nightshade species characterized by their lack of prickles and stellate hairs, their white flowers, and their green or black fruits arranged in an umbelliform fashion. The "Solanum" species in this group can be taxonomically confused, more so by intermediate forms and hybridization between the