An illustrated key for the identification of pollen from Rajaji National Park, India

Abstract

Accurate identification of pollen grains is fundamental to diverse fields such as palaeobotany, melissopalynology, aerobiology, and forensic science. This study presents a comprehensive illustrated key for the identification of pollen from Rajaji National Park (RNP). The park is situated in the Shivalik foothills of the Garhwal Himalaya, a region renowned for its rich floral diversity and significant ecological value. Extensive field surveys were conducted from 2021 to 2024, and polliniferous material from 302 plant species, representing 229 genera and 67 families, was collected. Pollen grains were prepared following the standard acetolysis protocol and subsequently examined using both light microscopy (LM) and scanning electron microscopy (SEM). Based on dispersal units and aperture type, the taxa were classified into 24 distinct pollen classes. An illustrated pollen identification key was developed, comprising a general key to differentiate pollen into distinct classes, followed by separate keys for each class. This key serves as a foundational reference for palynological research in Himalayan foothills. The work addresses a critical gap in regional palynological studies and contributes to strengthening pollen databases in India.