Kenya and Tanzania; woodland, damp forest understory or secondary scrub; 2100-3000 m elevation.
Solanum phoxocarpum is a member of the Old World clade of the spiny solanums (Leptostemonum), and within that group it belongs to a strongly supported Aculeastrum Clade along with Solanum aculeastrum and Solanum thomsonii (Vorontsova et al. 2013).
Levin, R. A., N. R. Myers, and L. Bohs. 2006. Phylogenetic relationships among the “spiny solanums” (Solanum subgenus Leptostemonum, Solanaceae). 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
Local Names. Kenya: Osigawai, Sigawet (Masai language).
Uses. Fruits used medicinally; plants used as hedges.
Solanum phoxocarpum is sympatric with the closely related S. aculeastrum, and can be distinguished by the unusual cylindrical pointed fruits, subentire leaves on fertile branches, and mauve flowers; the two species frequently grow together in woodland above 2100 m. Solanum aculeastrum has more deeply lobed leaves and abundant prickles, while S. phoxocarpum has entire leaves and fewer prickles.
Udo Dammer also recognized the distinctness of these plants and annotated the sheet Scheffler 306 (K) as “Solanum sepiaceum Dammer var. fructile verrucans spec. nov.” in his handwriting, with a printed label “Brit. Uganda. Station Lamuru. Buschiges Hochland. b.c. 3000 m”. This name does not seem to have been published and the specimen is not cited in the protologue of S. sepiaceum. “Station Lamuru” most likely refers to Limuru in central Kenya.