Solanum L.

Genus with a cosmopolitan distribution composed of about 1,300 species, most of which are native to the Old World. In North Africa it is represented by 20 species of shrubs, subshrubs, or herbaceous plants with stems with a lignified base, native or naturalised. To these, S. rostratum Dunal must be added, an herbaceous introduced but naturalised species. Among the native 4 are shrubby and will be described later. Other 3 species are herbaceous perennial with base sometimes woody, they are:

S. nigrum and S. villosum present stems up to 1 m height, herbaceous, sometimes suffruticose at the base, and flowers not more than 10 mm in diameter. They are plants from cultivated, ruderal and nitrophilous areas, common throughout North Africa. S. nigrum has black berries and eglandular indumentum, while S. villosum has yellow or orange berries and glandular or eglandular indumentum.

S. sinaicum is a subshrubby or perennial plant with a woody base, up to 40 cm in height, with flowers 10-15 mm in diameter and black or red berries; endemic to Israel, Jordan and Egypt, where it is found in fissures of rocks and beds of wadis in the Sinai Peninsula.

All these species are rare but widely distributed. Currently, they have not been assessed at a global level in the IUCN Red List of Threatened Species. In the Red List of vascular plants of Egypt (Flora Aegyptiaca Vol 1, 2000) S. villosum y S. sinaicum are listed as “Vulnerable”.

Non-native species but in some cases already widely distributed in North Africa are:

S. bonariense L., a shrub, also unarmed, up to 2 m in height, that is distinguished from S. schimperianum mainly by its leaves, with an elliptic leaf blade, with flowers 25-30 mm in diameter with blue-violet corolla, arranged in compound cincinni, and by its fruits, 10-12 mm in diameter. It is native to South America and is grown as an ornamental; it has escaped from cultivation and is now naturalised in various parts of North Africa.

S. linnaeanum Hepper & P.-M.L.Jaeger (S. sodomeum auct., non L.) and S. elaeagnifolium Cav. are 2 subshruby species more, not indigenous to North Africa, but already naturalised and widely distributed in the region. They are easily distinguishable because S. linnaeanum has a calyx that, as the rest of the plant, is densely covered with spines, while S. elaeagnifolium has an unarmed calyx, as is the case of S. forskalii and S. incanum. It can be distinguished from them for having much narrower leaves, for its straight, not curved spines and for its larger corolla. S. linnaeanum is native to the S of Africa and has become naturalised in almost all coastal regions of Morocco, Algeria, Tunisia and Libya. S. elaeagnifolium, native to America (from Argentina and Chile to the USA), has become naturalised in Morocco, Tunisia and Egypt.

S. aethiopicum is an herbaceous plant with stems lignified at the base, glabrous or tomentose, unarmed or with some spines, with ovate or ovate-lanceolate leaves and white corolla c. 15 mm in diameter; its edible fruits are variable in shape and colour, reaching up to 6 cm in length, from which there are numerous cultivars. Species escaped from cultivation in Tunisia and Egypt and is apparently naturalised in Egypt.

The following key includes the shrubby and larger perennial species, both native (in bold) and some introduced naturalised species that are increasingly common (even invasive) that are worth differentiating and, where applicable, should be eradicated.

Updated by: B. Valdés.