Palynological studies in combination with conventional morphology have a significant role in solving problems relating to plant systematics. Scanning electron microscope (SEM) is a useful tool for palynological studies with increased accuracy and precision. The pollen size, shape and details of sculpturing of the exine are of taxonomic value. The main objective of the present study was to provide a detailed morphological account of pollen grains of 37 herbaceous plant species from Amritsar, North-Western Punjab, India with the aim to extend knowledge of their morphology. A considerable variation for both the polar (P) (13.66 to 181.16 µm) and equatorial (E) diameter (11.68 to 149.53 µm) was observed for pollen of different herbaceous plant species studied. P/E ratio varied from 1.001 to 1.725. Among 37 plant species studied, the prolate spheroidal shape of pollen was observed in maximum number of species (21) followed by subprolate (10), prolate (5) and only a single species, Verbena pulchella L. showed spheroidal type of pollen. The small pollen grains were observed in a maximum number of species (13) and only a single species, Antirrhinum mazus L., showed very large pollen grains. Ten different types of exine sculpturing were observed in the present study.

Keywords: Exine ornamentation, herbaceous, palynology, scanning electron microscope.