Analysis of flora families with a small number of species in Samaro-Ulyanovsk Volga region

The flora families of physical-geographical areas of Samara-Ulyanovsk Volga region, including one, two and three species in the family spectrum, are considered. It is shown that with an increase in the number of species in the floristic sample, the percentage of species decreases. The nature of this dependence is shown in more detail for two physical-geographical regions of Samara Trans-Volga Soksky (forest-steppe zone) and Irgiz (steppe zone). The most pronounced decrease in the number of species in families is observed at the boundary of 400 species, as well as 600 species. The most significant share in the floristic sample is made up of families containing one species.