Аннотация:[On taxonomic value of stomatal characteristics and evolution of the stomatal complexes in flowering plants]
On the basis of literary data and results of author's investigations the stomatal polymorphism on one plant has been concluded to be widespread among the flowering plants. An opinion is supported that taxonomic and diagnostic value of stomatal characteristics in the flowering plants is considerably overestimated. On the example of the Amaranthaceae the author shows that: (a) the structure of the stomatal complexes may considerably depend on their location on the plant body; and (b) the stomatal evolution in a taxon may be mainly realized by the change of frequences of different stomatal types rather than by the transformation of one stomatal type to another. This poses essential difficulties in the clarification of trends in the stomatal evolution.