The paper assesses the ontogenetic tactics of formation of morphological indicators of the leaf blade of Betula pendula Roth in the environmental conditions of the city. When growing conditions deviated from the optimal for B. pendula, a divergent ontogenetic tactics of features characterizing the leaf blade shape, namely elongation indicator, correlation indicator of the widest part location, correlation of leaf blade width in its middle part to the maximum width, numerical indicators of the apex and base shape was revealed. The revealed ontogenetic tactics should be considered adaptive.

Shtirts Yu.A.