Floral morphometrics ofSolanumL. (Solanaceae) species in southern Western Ghats: correlation with interspecific taxonomic affinities

The taxonomic complexity of species in terms of classical, experimental and numerical factors associated with the section Solanum, the type member of Solanaceae, has long been accepted. The present study displays a morphometric approach of both spiny and non-spiny Solanum spp. (16 species and one variant accession) distributed in the southern Western Ghats of Kerala using the qualitative and quantitative floral characteristics. All the recorded species had distinct and discrete floral morphometric features. Analysis of the UPGMA phenogram and the scatter plot reveals three species clusters and three independent species in non-clusters; namely, Solanum wendlandii, Solanum macrocarpon and Solanum americanum. The species clusterings have been interpreted in the light of the qualitative and quantitative floral features. The two accessions of Solanum capsicoides (spiny and lax spiny), though clustered together were found to have differences in the distribution of spines on stem and calyx as well as in the nature of leaves. They also differ in significant floral traits such as stigma protrusion and apex of sepals. The protruded stigma is characteristic of spiny accession. The apex of sepals was acute in lax spiny accession and acuminate in spiny accession. Evaluation of the distant positions of S. americanum, S. wendlandii and S. macrocarpon in the phenogram and scatter plot reveals their segregation from the other species. True species co-ordination and species clustering revealed the lines of taxonomic affinities shared among the studied species and will provide support in the taxonomic revision of the genus Solanum.