The post‐industrial habitats provide previously unknown conditions for plant and vegetation development. We asked the question: do the extreme soil substrate conditions cause differences in chemical composition of cell walls of leaves in three grass species: Calamagrostis epigejos (L.) Roth, Phragmites australis (Cav.) Trin. ex Steud, and Molinia caerulea (L.) Moench? With the use of immunohistochemical methods we determined the spatial distribution of selected pectic and AGP (arabinogalactan proteins) epitopes within leaf tissues of grass species growing in two industrial and control (meadow) habitats. Some post‐industrial habitats increase biodiversity. Fast adaptation and divergence cause phenotypic changes. This process has been recently recorded and is called human‐induced rapid evolutionary changes. The levels of pectins and arabinogalactan proteins increased on the post‐industrial habitats in comparison to the control sites. On control habitat, pectic epitope with galactan chain residues (recognised by the LM5 antibody) was not detected in cell walls of Calamagrostis epigejos leaves, but was abundantly present in Phragmites australis leaves. The pectic epitope with arabinan residues (recognized by LM6 antibody) was less represented in cell walls of Molinia caerulea leaves. AGP epitope, recognised by LM2 antibody, was abundant only in Ph. australis. In Molinia caerulea this epitope was not detected. The AGP epitope recognised by JIM13 antibody was observed in all analysed species. The results obtained revealed the response of grass individuals to different environments: a) varied responses to different soil substratum conditions (novel ecosystems), and b) that this reaction is species‐specific with respect to the analysed cell wall components.