Microscope images of Carex pendula - cross-sections of roots and leaves

This dataset comprises light microscope images of cross-sections of Carex pendula roots cultivated in biochar-sand filters used for wastewater treatment. The experiment was conducted between July and October 2025. Four lisymeters (L1-L4) with diverse biochar/sand proportion were used: L1 - 100% sand, L2 - 1% vol./vol. of biochar addition into sand, L3 - 5% vol./vol. of biochar addition into sand, and L4 - 10% vol./vol. of biochar addition into sand. Biochar made from chicken manure (pyrolyzed at 450 °C) was pre-rinsed with water and applied in the lysimeters. Delta Optical Generic Pro microscope with camera 3MP (Delta Optical, Poland) integrated with DLTCamViewer software was used for observation.