Solanum cerasiferum
Not known
Across northern Sub-Saharan Africa from Senegal to Cameroon, Chad (fide Brundu & Camarda 2013), South Sudan, Sudan, and Ethiopia, very common in Sudan; growing in fallow land, scrubland, and woodland; 450-1200 m elevation.
Solanum cerasiferum is a member of the Eggplant clade (part of the Old World clade of the spiny solanums, subgenus Leptostemonum) and a relative of the cultivated eggplant, Solanum melongena (Vorontsova et al. 2013; Knapp et al. 2013)
Bitter, G. 1923. Solana Africana. IV. Repert. Spec. Nov. Regni Veg., Beih.. 16: 1-320.
Brundu, G., Camarda, I. 2013. The Flora of Chad: a checklist and brief analysis. PhytoKeys 23: 1-18. doi: 10.3897/phytokeys.23.4752
Heckel, E. 1890. Une nouvelle espèce de l’Afrique tropical, Solanum duchartrei. Rev. Gén. Bot. 2: 49-54.
Knapp, S., and M.S. Vorontosova. 2013. From introduced American weed to Cape Verde Islands endemic – the case of Solanum rigidum Lam. (Solanum, subgenus Leptostemonum). PhytoKeys 25: 35-46.
Olet, E. A., and R. Bukenya-Ziraba. 2001. Variation within the Solanum incanum complex in Uganda and its relationship with Solanum cerasiferum. In: van den Berg R. G., Barendse G. W. M, van der Weerden G. M., Mariani C., eds. Solanaceae V: Advances in Taxonomy and Utilization. Botanical Garden of Nijmegen: Nijmegen University Press, 97-108.
Vorontsova, M.S. and S. Knapp. 2012. A new species of Solanum (Solanaceae) from South Africa related to the cultivated eggplant. PhytoKeys 8: 1-11.
Vorontsova, M. S., and S. Knapp. 2012. Solanum spp. 26-45, 52-62, 65-66. In: J.M. Edmonds, Solanaceae, Flora of Tropical East Africa. Kew: Royal Botanic Gardens, Kew.
Vorontsova, M. S., S. Stern, L. Bohs, and S. Knapp. 2013. African spiny Solanum (subgenus Leptostemonum, Solanaceae): a thorny phylogenetic tangle. Bot. J. Linn. Soc. 173: 176-193. doi:10.1111/boj.12053
Local Names. Sudan: Kaderabas (Arabic, Simpson 7086).
Solanum cerasiferum is a slender prickly herb with long inflorescences and up to 3 long-styled flowers and fruits per infructescence; plants exhibit weaker andromonoecy than other members of the eggplant clade such as S. incanum (Vorontsova et al. 2013). Populations appear to be either glabrescent or moderately stellate-pubescent. Members of the eggplant clade are difficult to distinguish morphologically (Knapp et al. 2013) and it is not clear if populations of S. cerasiferum as recognized here include some plants with hybrid origins. Future study at the population level across Africa will be necessary to unravel this complex group.
Solanum cerasiferum has been confused with S. melongena, S. incanum, S. dasyphyllum, as well as S. aethiopicum, and many historical specimens of S. cerasiferum are annotated as “S. xanthocarpum” (a name applied to many specimens of prickly Solanum, but correctly a synonym of the Asian species S. virginianum L.). Solanum cerasiferum is a less robust plant than S. incanum or S. campylacanthum. Crossing and numerical taxonomy studies (Olet & Bukenya-Ziraba 2001) suggest that S. cerasiferum and S. campylacanthum (as “incanum”) belong to the same biological species and the only significant morphological difference is the absence of indumentum in S. cerasiferum. Review of large numbers of collections from across central Africa suggests that populations seemingly intermediate between S. cerasiferum and S. campylacanthum with a robust habit and densely stellate-pubescent leaves with acute lobes (segregated by Richard Lester as S. beniense, a name we consider here as a synonym of S. campylacanthum ) are found in northern Democratic Republic of the Congo and Uganda.
Glabrous-leaved populations of S. cerasiferum are reminiscent of S. melongena and S. aethiopicum, but with more prickles and deeper-lobed obtuse to acute leaf lobes (versus almost entire leaves with rounded lobes in S. melogena and S. aethiopicum). Solanum cerasiferum is also morphologically similar to S. rigidum from the Cape Verde Islands as well as the South African S. umtuma (see Vorontsova & Knapp 2012; Knapp & Vorontsova 2013), but differs from the former in its shorter calyx lobe and the latter in its less decurrent leaves.
Solanum crepinii was described from an un-numbered collection made by F.W. Sieber from “Senegambia”; S. crepinii was cited from “hb. propio Sieberiano, hodie in hb. Van Heurckiano” indicating two specimens were used (Van Heurck 1870). The Van Heurck herbarium (including Sieber’s herbarium) was transferred on permanent loan to BR (from AWH) in 2006 (http://www.br.fgov.be/PUBLIC/GENERAL/HISTORY/herbariumchronology.php), so it is likely that these specimens are now in BR.
A single specimen in the herbarium of the Faculty of Sciences in Marseille (now MARS) was cited in the protologue of S. duchartrei. In addition, reference was made to plants grown in the gardens of Paris and Marseille (Heckel 1890); the illustration accompanying the protologue appears to be from living plants and is clearly S. cerasiferum.
None of Bitter’s (1923) descriptions of the varieties of S. cerasiferum cites herbaria, so we have chosen the best preserved duplicates of the collections he cited as lectotypes. In describing S. cerasiferum var. kerense Bitter cited two collections, Steudner 721 and Steudner 722; no specimens of Steudner 721 were found, hence the K sheet of Steudner 722 was chosen as the lectotype.