This paper brings a contribution to the knowledge of vegetal organisms that participate in the processes of self-cleaning in the urban sector of Nicolina river. By periodical outings on the field, observations on the field and in laboratory, we have identified species of aquatic and paludous macrophytes in the composition of water biocenosis of Nicolina river and algae taxons in the periphyton of some dominant or frequent aquatic and paludous macrophytes. We identified 28 species of superior macrophytes (paludous, aquatic); most of them are perennial species and prefer a sub-layer rich or excessively rich in mineral nitrogen. In the periphyton, the species of Phylum Bacillariophyta are predominant. The species taken into account fulfil numerous ecological services and are essential to assure the dynamic balance of the aquatic ecosystem.