Taxonomic Implications of Leaf Anatomical Patterns in Riparian Apocynaceae Species
Abstract
Aim of study: This study described micro magnified anatomical variable patterns to understand the complex relationship between the macroscopic and microscopic features of leaves within the riparian Apocynaceae species. Area of study: The biomagnification process provides crucial insights into the structural adaptations and ecological roles from riparian zone of Punjab. Material and method: Comparative foliar anatomical features of 25 Apocynaceous taxa were examined using light microscopy and scanning electron microscopy (SEM) to document epidermal characteristics and trichome diversity. Main results: Both surfaces of the leaves exhibited differences in their leaf anatomical traits including type of stomata, epidermis, anticlinal wall, lobes and diversity of trichomes. The epidermal cells shape reported as irregular, rectangular, polygonal, undulated, isodiametric and uniseriate. The largest epidermal cells were examined in Vinca major (59.6 µm) and (77.6 μm) on adaxial and abaxial surfaces respectively. Largest stomatal complex was recorded for Beaumontia grandiflora (48.6 µm) while smallest for Cryptolepis dubia (13.2 μm). The maximum stomatal index (SI) was calculated (37.2%) in Asclepias curassavica. Multicellular non-glandular trichomes were observed on both surfaces of Beaumontia grandiflora while uniseriate trichomes located in inter-coastal zone in Trachelospermum jasminoides especially on the abaxial surface. The longest trichome length was measured for Pergularia tomentosa (135 µm) along adaxial side, while along the abaxial surface, maximum length was calculated for Asclepias curassavica (262 µm). Research highlights: The study using LM and SEM, key taxonomically relevant features including trichome types, stomatal complex arrangements, and epidermal cell patterns were identified. These micromorphological markers proved valuable in distinguishing closely related species and contributed to the development of diagnostic taxonomic keys.