Epiphytic lichens play a key hydrological role in ecosystems by intercepting and retaining water. These attributes can be characterized at an individual thallus scale by considering the retention and loss rates of water, themselves influenced by growth form and anatomy. We compared the hydrological attributes (water-holding capacity and standard drying rate) of two common northern temperate-boreal lichen genera, Evernia and Usnea, which differ greatly in internal anatomy. Despite conspicuous morphological and anatomical differences between the taxa that were hypothesized to affect thallus-water dynamics, their hydrological traits were found to be remarkably similar. This suggests either limited influence of internal anatomy on these ecologically relevant traits or convergence in hydrological attributes in co-occurring taxa.