Madagascar, endemic to northern Antsiranana; growing in tropical forest on limestone; 0-300 m elevation.
Solanum mahoriense is a member of the Leptostemonum clade ((Levin et al., 2006; Weese & Bohs, 2007). Within that group it belongs in the somewhat well-supported Madagascar Clade (Vorontsova et al. 2013) with other Malagasy endemics.
Solanum mahoriense is a striking instantly recognisable species with large ornately lobed leaves, long-filiform calyx lobes, and the solitary berries fully enclosed by an inflated, accrescent, densely prickly calyx. The berry has a strong perfume-like scent, and the cut surface of the berry has a tomato-like odour (D’Arcy and Rakotozafy 1986). There are no obvious morphological similarities with other Solanum species in Madagascar, although an enlarged prickly calyx is also found in the small-leaved S. toliaraea in southwestern Madagascar.
D’Arcy and Rakotozafy (1994) tentatively included S. mahoriense in section Cryptocarpum Dunal together with the New World species S. sisymbriifolium which also has an accrescent calyx and ornately-lobed leaves, but recent molecular work shows that S. mahoriense is a member of an monophyletic Madagascan clade well embedded in the Old World Clade of subgenus Leptostemonum (Vorontsova et al. 2013), while S. sisymbriifolium groups with other New World taxa (Stern et al. 2011).
D’Arcy, W.G., & A. Rakotozafy 1994. Solanaceae. Famille 176, pp. 1-146. In Flore de Madagascar et des Comores, P. Morat (ed.). Muséum National D’Histoire Naturelle, Paris.
Levin, R.A., N.R. Myers, & L. Bohs 2006. Phylogenetic relationships among the "spiny" solanums (Solanum subgenus Leptostemonum). Amer. J. Bot. 93: 157-169.
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
Weese, T.L. & L. Bohs 2007. A Three-Gene Phylogeny of the Genus Solanum (Solanaceae). Syst. Bot. 32(2): 445-463.