We investigated the radiocaesium content of nine epiphytic foliose lichens species and the adjacent barks of <italic>Zelkova serrata</italic> (Ulmaceae, "Japanese elm") and <italic>Cerasus</italic> sp. (Rosaceae, "Cherry tree") at the boundary of the Fukushima Dai-ichi Nuclear Power Station six years after the accident in 2011. Caesium-137 activities per unit area (the ¹³⁷Cs-inventory) were determined to compare radiocaesium retentions of lichens (65 specimens) and barks (44 specimens) under the same growth conditions. The ¹³⁷Cs-inventory of lichens collected from <italic>Zelkova serrata</italic> and <italic>Cerasus</italic> sp. were respectively 7.9- and 3.8-times greater than the adjacent barks. Furthermore, we examined the radiocaesium distribution within these samples using autoradiography and on the surfaces with an electron probe micro analyzer (EPMA). Autoradiographic results showed strong local spotting and heterogeneous distributions of radioactivity in both the lichen and bark samples, although the intensities were lower in the barks. The electron microscopy analysis demonstrated that particulates with similar sizes and compositions were distributed on the surfaces of the samples. We therefore concluded that the lichens and barks could capture fine particles, including radiocaesium particles. In addition, radioactivity was distributed more towards the inwards of the lichen samples than the peripheries. This suggests that lichen can retain ¹³⁷Cs that is chemically immobilised in particulates intracellularly, unlike bark.