Abstract: Disagreement exists among research workers in regard to the taxonomic relationship among three Chinese endemic species of Hemerocallis : H. plicata , H. forrestii and H. multiflora. The present authors attempt to resolve this problem based on a study on karyotypes. The karyotype formulas of H. plicata, H. forrestii and H. multiflora are respectively 2n = 12m + 8sm + 2T, 2n = 8m + 12sm + 2T and 2n = 12m + 4sm + 4st + 2T, in which the T chromosomes (No 11 ) of all the three species have microsatellites at the centromeric end. The Euclidean distances of chromosome complements are 0. 2728 between H. plicata and H.forrestii ,0. 4501 between H. plicata and H. multiflora and 0. 5741 between H. forrestii and H. multiflora. These data clearly indicate that H. plicata is more closely related to H. forrestii than to H. multiflora, and that H. multiflora is more advanced thanthe other two species,for the karyotype of H. multiflora is more asymmetical.

Key words: Hemerocallis, Chinese endemic species, Karyotype