As a supplement to chromosome information published in the book entitled "Caryology of the flora of Sakhalin and the Kurile Islands" (Probatova, Barkalov, Rudyka 2007), the chromosome numbers for 57 vascular plant species from Sakhalin and the Kurile Islands (44 genera, 21 families), are presented here. Twenty-two species were added to the Annotated list in the book mentioned above. Chromosome numbers are reported for the first time in the following six species: Cardamine sachalinensis, Elymus franchetii, Minuartia barkalovii, Oxytropis calcareorum, Persicaria extremiorientalis, Popoviocodonia stenocarpa (the first chromosome information for the genus Popoviocodonia). Additionally, new cytotypes are revealed in three species: Lathyrus pilosus, Oxytropis hidakamontana, and Potentilla matsumurae.Biodiversity and Biogeography of the Kuril Islands and Sakhalin vol.
