To the question of weeds on flower beds of St. Petersburg

The purpose of the study was to identify the species composition of weeds in flower beds. In 2020, 17 flower beds were surveyed on the territory of St. Petersburg. Floristic analysis of the data obtained, calculation and assessment of the occurrence of species were carried out. The analysis revealed 110 species of weed plants from 80 genera and 26 families. The main number of species and genera belong to 8 and 7 families, respectively. In terms of life expectancy, a slight predominance of juvenile species was observed (53.64%). According to the occurrence indicators, species are distributed according to the classes of constancy (I class – 66 species, II – 20, III – 9, IV – 11, V – 4). The group of dominant by occurrence is formed by 24 species (III, IV, V constancy classes). The group of concomitant by occurrence is formed by 20 species (II constancy class). The examined flower beds revealed the presence of 33 species of weeds that dominate the fields of grain and row crops in the Leningrad Region. A number of alien species were found, among which there are both burdensome weeds and an invasive species.