Karyotypes of 15 species ofCyanotisare reported.C. adscendens(2n= 48) is a tetraploid. The remaining species are diploids having 2n= 24 or 20 or 16 chromosomes. Adaptations for self pollination, and annual growth habit are cited as reasons for the low incidence of polyploidy inCyanotis. C. pilosa(2n= 24; n.f. 30) is shown to be the nearest among the reported taxa to the most primitive species in the genus—C. villosa. C. wightii(2n= 24; n.f. 32) is shown to have a more symmetrical karyotype than the above two.C. arachnoidea, C. cristata, C. fasciculata, C. longifoliassp.longifoliavar.rupicola, C. nodiflora, C. obtusaandC. vaginata, all with 2n= 24; n.f., 26, have asymmetrical karyotypes.C. tuberosa, C. sarmentosa(2n= 24) both having n.f. 24 andC. adscendens(2n= 48; n.f. 48) have highly asymmetrical karyotypes. Karyotype ofC. papilionacea(2n= 16; n.f. 20) is shown to be nearer to the arachnoidea type inspite of the reduction in chromosome number. The above species groups, are suggested to have evolved stepwise by centric fusions or unequal translocations or pericentric inversions from the ‘villosa’ type. Segregation of these into subgeneric units on the basis of karyotype differences is suggested to be untenable owing to the lack of a parallel morphological discontinuity. The highly asymmetrical karyotypes ofC. axillarisandC. cuculiata(2n= 20; n.f. 20) are shown to support the creation of a separate sectionOcreaflorainCyanotisfor them.