Blackcurrant material from the gooseberry ("Ribes grossularia"), the red currant ("Ribes rubrum") and the flowering currant ("Ribes sanguineum"). The resulting offspring were further back-crossed to "R. nigrum". Cultivars produced include 'Tisel' and 'Tiben' in 2000 and 'Ores', 'Ruben' and 'Tines' in 2005. Further cultivars 'Polares' and 'Tihope' are being tested. Since 1991, New Zealand has become an important centre for research and development, as its temperate climate is particularly suitable for cultivation of the crop. Breeding programmes are concentrating on yield, large fruit size, consistency of cropping and upright habit. In North America, there is a need for this fruit to
Solanum nigrum in the unripe green berries, and immature fruit should be treated as toxic. Most cases of suspected poisoning are due to consumption of leaves or unripe fruit. There are ethnobotanical accounts of "S. nigrum" leaves and shoots being boiled as a vegetable with the cooking water being discarded and replaced several times to remove toxins. Some of the uses ascribed to "S. nigrum" in literature may actually apply to other black nightshade species within the same species complex, and proper species identification is essential for food and medicinal uses (See "Taxonomy" section). "S. nigrum" has been widely used as a