On the new species of early-spring buttercups from the south of Yenisei Siberia
The descriptions of the four new species of Ranunculus from the subsection Cassubici Tzvelev collected in the south of the Krasnoyarsk Territory and in Republic of Khakassia are presented. The locations are confined of various mountainous altitudinal zones of the Kuznetsk Alatau, Western and Eastern Sayan. All new species -Ranunculus manensis Stepanov, Ranunculus bujbensis Stepanov, Ranunculus kedranus Stepanov and Ranunculus sobakus Stepanov are early spring and occurs in humid environment from low to high mountains. Information on ecology and distribution of the new species, and comparison with similar species are given. Described species were studied under cultivation, where they showed constancy of taxonomically significant characters. Hybridization phenomena with related species were not observed.