Systematic implication of trichome morphology in alpine flora from Hindukush Mountain range

This study aimed to investigate trichome diversity in alpine flora from the Hindukush Mountain range of Pakistan, and the possible taxonomic potential of trichome diversity in the identification of plant species. Plant specimens were collected from the alpine regions of Swat Pakistan. The present study explain micromorphological features of foliar epidermal trichomes of 70 species in 52 genera belonging to 25 families of dicots. Using nitric acid protocol both abaxial and adaxial surfaces were studied under light microscope. Two types of trichomes were observed during microscopy; i.e., non-glandular and glandular. Non-glandular trichomes were mostly unicellular, cylindrical, or conical while glandular trichomes were mostly capitate. Furthermore, trichome shapes ranged from unicellular short to unicellular cylindrical which were very long, and from bicellular to multicellular, multiseriate, falcate, conical, stellate, dendritic, peltate, capitate. A total of 27 different types of trichomes were observed indicating the enormous variation in trichomes morphology and their physiological roles. This diverse array of trichomes provides sufficient information of systematic and evolutionary significance. The results of qualitative and quantitative micromorphological features have been described and tabulated. In addition, for easy and fast identification diagnostic key was constructed based on studied traits. From this study, it is concluded that alpine plants growing in hostile habitats have developed various kinds of trichomes to cope with harsh climates and predators, which also provide considerable taxonomic data for species identification, diagnosis, and circumscription.