Foliar epidermal micromorphology: a contribution to the taxonomy of family Oleaceae

Oleaceae (olive family), includes 28 genera and about 700 species. Nevertheless, there remains a lot to uncover about the group’s historical development, the evolution of various reproductive and dispersal mechanisms, and polyploidization episodes appear to be linked to its diversification. In the current study, foliar epidermal anatomy of 13 plant species and 2 varieties from 7 genera of Oleaceae was examined under a light microscope. The qualitative and quantitative features like stomatal density, size,shape of guard cell, number of epidermal cell, subsidiary cells, and structure and density of trichomes were analysed using a light microscope. This was the first study on the foliar micromorphology of various Oleaceae taxa. Almost all species exhibited hypostomatic type except one in which Amphistomatic type was observed. Most of the stomata were anomocytic while some Paracytic and one diacytic stomata were also seen. Maximum stomatal length of (30.80 + 1.44 μm) and lowest of (18.30 + 0.21 μm) was noted. All trichomes observed were unicellular. Both glandular and non-glandular trichomes were observed with highest trichome length (237.75–248.00 = 242.25 + 1.73 μm) and the lowest (100.00–101.75 = 100.75 + 0.32 μm). Plant taxonomists might commence their future research with the micro-morphological aspects of foliar epidermal morphology, which exhibit a number of innovative qualities for accurate taxonomic identification.