Treatment of seedlings ofPimpinella monoecia with colchicine-gammexane lead to the production of tetraploids. The tetraploids besides showing the meiotic anomalies like univalents, split spindles, multiple spindles, micro-nuclei, nondisjunction, strays, etc., exhibited pollen grains which were triradiate, triangular and quadriradiate while the controls had only one type of bipolar radiosymmetric grains. They have been classified into different types and their frequency has been determinod. A scheme has been presented representing the development of these variable grains from the control type A, which is based on the observation of grains showing intermediate stages. Explanation of this pollen variability has been presented.