Abstract
Cytogenetic investigation was carried out to clarify cytogeographic distribution of two cytotypes with different ploidy level, and to speculate chromosomal differentiation of Goodyera foliosa in southwest Japan. All observed individuals in G. foliosa var. foliosa had tetraploid number of 2n=56, while the all individuals in G. foliosa var. laevis had diploid number of 2n=28 and tetraploid number of 2n=56. Total chromosome lengths at metaphases in tetraploids in the both varieties were nearly twice as long as those of the diploids. In G. foliosa var. laevis native to Hiroshima Prefecure, cytogeographic investigation showed that the tetraploid populations were located more west than those of diploids.