EN
Grasses are the clonal plants of modular structure. Formation of the tussock grasses and the system of numerous branching in stoloniferous grasses is realized by multiple repeatibility of the basic units - modules. The clonal growth is accompanied by simultaneous processes of plant growth and death. Persistence, understood as a sustained maintenance of the species in meadow plant community, is the notion very wide and complicated; it includes the complex of problems to be considered just on the onthogenetic and population levels.