Solanum wrightii
Not known
Native to the eastern Andean slopes of Bolivia (Nee 1999; F. Farruggia, pers. comm.) from in primary and secondary tropical forest and savanas, in the floodplain or in terra firme, disturbed areas and riparian areas. Widely planted as a shade tree in mid-elevation regions in eastern Africa, apparently not escaping and naturalizing; originally described from Hong Kong and commonly escaped in South China.
Solanum wrightii is a member of the Crinitum Clade of subgenus Leptostemonum (Stern et al. 2011).
Nee, M. 1999. Synopsis of Solanum in the New World. Pp. 285–333 in M. Nee, D. E. Symon, R. N. Lester & J. P. Jessop (eds.), Solanaceae IV: Advances in Biology and Utilization. Royal Botanic Gardens, Kew.
Stern, S. R., M. de F. Agra, and L. Bohs. 2011. Molecular delimitation of clades within New World species of the ”spiny solanums” (Solanum subgenus Leptostemonum). Taxon 60: 1429-1441.
Local Names. Bolivia: tsimac (Guareco 578); Africa. Potato tree (Burkhill 1985). Tanzania and Kenya: Tree tomato, Uganda tree solanum, isuke (Pimbwe language).
Uses. Ornamental shade tree.
[discussion based on distribution and ecology in Africa - to be completed]
Solanum wrightii is very commonly planted as a shade or street tree throughout tropical Africa, but apparently has not naturalized widely. Some specimens from Tanzania (e.g., Mhoro 5694, MO; Kanywa 30, EA) indicate the plants were found in forest, so perhaps this species is in the process of becoming naturalized. On the other hand, these long-lived trees may be remnants of previous plantings. It is native only to a very narrow region of eastern Bolivia (F. Farruggia, pers. comm.), and it is not known how it came to be introduced to the Old World.
Solanum wrightii is not easily confused with other species in Africa; its tree habit and large leaves are distinctive. When non-reproductive, it can be confused with the less commonly cultivated S. chrysotrichum, but that species has more rusty pubescence and stellate rather than simple trichomes on upper leaf surfaces. In flower the two species are not confusable, S. chrysotrichum has smaller, stellate, white flowers. The large purple flowers of S. wrightii are similar to those of S. richardii, but S. richardii is a smaller, often scandent, plant that never becomes tree-like and has abundant recurved prickles on the stems and leaves.