Coastal Tanzania and northern Mozambique; growing in shrubland and disturbed areas; 0-300 m elevation..
Solanum lamprocarpum is a member of the Old World clade within subgenus Leptostemonum (Levin et al., 2006); within that group it belongs to large unresolved Anguivi Grade, and appears to be closely related to a group with S. anguivi and S. cyaneopurpureum (Vorontsova et al. 2013).
Solanum lamprocarpum is a rare species recognized by its foliaceous oblong calyx lobes with obtuse apices, elliptic or obovate lobed leaves that are reddish brown on herbarium specimens, straight prickles, erect woody flowering pedicels and trichomes with midpoints elongated to 0.7-1 mm long. Jaeger (1985) included S. lamprocarpum within S. zanzibarense, a circumscription not supported by our study (Vorontsova et al., 2013).
Solanum lamprocarpum is similar to S. zanzibarense and lies within its distribution range. Confusion is also possible with the morphologically similar S. inaequiradians, S. stipitatostellatum, and S. usaramense. Solanum lamprocarpum has lobed leaves and narrow corolla lobes similar to those of S. zanzibarense, but can be distinguished by its straight prickles (versus usually recurved or hooked stem prickles in S. zanzibarense), calyx lobes 8-10 mm long in fruit (versus calyx 2.5-4 mm long in flowers and fruit of S. zanzibarense), elliptic to obovate leaf shape (versus ovate to lanceolate leaf shape in S. zanzibarense), and trichomes with midpoints 0.7-1 mm long (versus trichomes with reduced midpoints in S. zanzibarense). The 0.7-1 mm trichome midpoints of S. lamprocarpum are almost as long as the 1.5-3 mm trichome midpoints of S. inaequiradians, but S. lamprocarpum can be distinguished by its straight stem prickles (versus hooked stem prickles in S. inaequiradians) and elliptic to obovate leaves (versus ovate leaves in S. inaequiradians). Solanum lamprocarpum differs from S. stipitatostellatum by its elliptic to obovate lobed leaves (versus ovate subentire leaves in S. stipitatostellatum), corolla ca. 1.7 cm in diameter (versus corolla 1.8-3 cm in diameter in S. stipitatostellatum), and trichomes with midpoints 0.7-1 mm long throughout the plant (versus trichomes with reduced midpoints, or midpoints occasionally elongated to 0.7 mm on the young stems in S. stipitatostellatum). Solanum usaramense is easily distinguished from S. lamprocarpum by its small hooked stem prickles and larger corolla.
Jaeger, P.-M.L. 1985. Systematic studies in the genus Solanum in Africa. PhD thesis, University of Birmingham, United Kingdom.
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