The cytology of nine W. Himalayan species belonging to three genera Arisaema, Sauromatum and Typhonium has been studied. There is considerable variation in chromosome size in the genus Arisaema. Diploid taxon of A. concinnum (2n=28) has been found to occur in the Kumaon hills. Bowden had earlier reported this species to be tetraploid with 2n=56. A. curvatum was found to possess 2n=28. Malik had earlier observed 2n=26 in this species. Previously only the diploid form of A. jacquemontii was known to occur (Malik 1961). Present investigations have revealed the existence of tetraploids based on x=13 in the Simla hills. Sauromatum venosum has 2n=26 and possesses a symmetrical karyotype. The base number x=13 is suggested for the genus.