Foliar LM and SEM Insights: InvestigatingEpidermal Features and Its TaxonomicImplications in Some Verbenaceae Taxa

The epidermal characteristics of the foliar of five species of the Verbenaceae family were examined using light and scanning electron microscopy. The use of the SEM method to investigate the foliar epidermal features of Verbenaceae family has not yet been reported in Pakistan. Therefore, the current study aims to investigate the anatomical characters for correct identification and taxonomic significance of the species within the family Verbenaceae. The result revealed that the plants exhibited variations in leaf epidermal features, including leaf cell size, stomata size, subsidiary cell size, and stomatal index. The studied species, with the exception of Duranta repens, are amphiostomatic i.e. they have stomata on both leaf surfaces. Normally, the stomata are anisocytic and animocytic and were observed on both leaf surfaces in most species. In Vitex negundo, the stomata were not visible as there were many tomentosa and glandular hairs. The shape of the epidermal cells was quite different on both leaf surfaces, with thick and straight epidermal walls in most species, except in Phyla nodiflora (L.) Greene, which has smooth epidermal walls. Glandular hairs were observed in Lantana indica Roxb, Vitex negundo L., and Verbena officinalis L. The trichomes in V. negundo are segmented and branched. The largest length (30-33 μm) of stomata was found on the abaxial surface of P. nodiflora, while the smallest length (6-12.5 μm) of stomata was observed in Lantana indica Roxb. The size of epidermal cells varied in both length and width on both surfaces of the leaves. The mean length of epidermal cells was higher on the upper epidermal cell than on the lower surface. The length of the epidermis on the abaxial leaf surface was greatest in Verbenaceae members (42-47.5 μm) in V. officinalis and not in the other species. These anatomical features were given special consideration in the characterization and identification of Verbenaceae taxa.