Solanum toliaraea
Not known
Endemic to Madagascar, the western coastal forests north of Toliara (Tuléar); thorn scrub on sand close to the sea, often in disturbed areas; 0-20 m elevation.
Solanum toliaraea was one of the first three spiny Solanum species from Madagascar to be included in molecular phylogenetic studies (Bohs, 2005) and is a member of the spiny Madagascar clade within the Old World clade (Levin et al., 2006). Recent analyses show it to belong to a somewhat well-supported Madagascar Clade (Vortonsova et al. 2013), and to be related to Solanum heinanum and Solanum bumeliifolium.
Bohs, L. 2005. Major clades in Solanum based on ndhF sequences. Pp. 27-49 in R. C. Keating, V. C. Hollowell, & T. B. Croat (eds.), A festschrift for William G. D’Arcy: the legacy of a taxonomist. Monographs in Systematic Botany from the Missouri Botanical Garden, Vol. 104. Missouri Botanical Garden Press, St. Louis.
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
Solanum toliaraea is a morphologically uniform narrow endemic, easy to recognize by its accrescent, inflated, prickly fruiting calyx. The calyx is moderately sized and unarmed at anthesis but expands to enclose the fruit, and prickles appear on its basal portion and spread to cover the entire surface of the calyx except the free apical lobes. The only other Madagascar Solanum species with a spiny inflated calyx is the large-leaved S. mahoriense from the wet northern forests.
Solanum toliaraea has no obvious close relatives but without a fruit it can be difficult to distinguish from the sympatric S. batoides: S. toliaraea differs from S. batoides in its leaves that are regularly ovate, concolorous, and yellow green (versus orbicular to elliptic or ovate, concolorous to discolorous yellow-green to brown-green leaves in S. batoides) and stem trichomes with 9-14 rays (versus 7-9 rays in S. batoides).