The present study was performed for the Himalayan medicinal species Sium latijugam on male meiosis, morphological parameters and distribution pattern of diploid as well as tetraploid cytotypes. Both diploid (2n=12) and tetraploid (2n=24) cytotypes were found in Kashmir, however, the tetraploid cytotype is new addition to the species for the first time. The tetraploids were restricted to higher altitudes and characterized by abnormal meiosis leading to high pollen sterility and formation of variable sized pollen grains. Additionally tetraploids were morphologically more luxuriant in comparison to their diploid counterparts.