Dermatocarpon luridum is a subaquatic lichen that grows on siliceous rocks around the margins of freshwater lakes and rivers and is distributed throughout the temperate climatic zone, but co-occurring species have not been documented. The goal of this study was to investigate the variability of the species in the surrounding habitat within 1 m of the lichen. Sixty-three species of lichens were collected from the same habitat as D. luridum, and 34 of those species were growing directly on the rock substratum.