Taxonomic significance of epidermal and venation characters in the genus Diospyros L. (Ebenaceae) in Nigeria

Abstract

This study investigated the foliar anatomy and venation patterns of thirteen species of the genus Diospyros in Nigeria with a view to identifying characters of great taxonomic value in the genus. Plant collections were made from different locations in Southwest Nigeria and the site of collection geo-referenced with a GPS device. Samples were identified at the Herbarium of Botany Department, Obafemi Awolowo University (IFE). Voucher Specimens were deposited in the herbarium and voucher number assigned to each of the species. The samples were subjected to foliar epidermal and venation examinations. Qualitative data were recorded as the quantitative data were subjected to statistical analysis and the characters vary significantly (P = 0.05). Epidermal and venation characters which separate the taxa include stomata type, size and index, shape and size of epidermal cell, trichome type, presence/absence of crystal/druses, as well as venation. Paxillate venation in D. suaveolens is diagnostic for the species. The presence of parenchymatous sheath over the veins and veinlets in D. tricolor is a spot character. The study reveals that leaf epidermal and venation characters are important in delimitation of species in the genus Diospyros.