Ranunculus kobendzae Halamski sp. nova (Ranunculaceae) is a representative of the partly apomictic R. auricomus complex and is characterised by undivided, reniform radical leaves with a very wide basal angle, segments of stem leaves with partly slender teeth, mostly imperfect flowers, and pilose, ovate to cylindrical tori (receptacles) with a marked intervallum. Similar microspecies of the R. auricomus complex are R. uplandicus, R. allemannii, R. ganeschinii, R. neumannii, R. zmudae and R. mendosus, but the combination of characters of radical and stem leaves of R. kobendzae is unique. At the type locality in Lipka (Dębina) near Warszawa (Warsaw, capital of Poland), R. kobendzae grows in an oak–hornbeam forest, and in three other locations in central Poland (Puszcza Słupecka, Brańszczyk and Błogie) in hornbeam or alder forests. The DNA ploidy level was determined by propidium iodide flow cytometry from a dried herbarium specimen and was found to be tetraploid (2n = 4x).