Plant cell walls are integral components of living cells, undergoing dynamic changes in response to internal as well as external stimuli. The revival of studies on plant walls has led to the situation where re-definition of a concept of ?plant cell? is necessary. In this paper the current knowledge on plant walls is presented and differentiated understanding of the position of cell walls in plant cells is revealed. Starting from the analysis of basic tenets and corollaries of cell and organismal theories describing organisation of biological systems, an organismal model for interpretation of plant cell concept is proposed. On that basis an integral presence of cell walls in the architecture of plants and plant cells is indicated.