Lantzius-Beninga (1815-1871) demonstrated that species could be distinguished using the peristome. Although this discovery has important implications, it has not been widely adopted. To test Lantzius-Beninga's theory, the peristome in the Dicranales was compared with the Grimmiales as outgroup. In total, 81 samples from 20 species in 14 genera from 6 families were investigated using longitudinal sections and SEM. The Dicranales, a monophyletic group, are thought to be recently evolved with a rapid radiation occurring after peristome apparition. The classification of the Dicranales remains unresolved and novel characters could provide useful insights into their relationships. The species investigated had different peristome architectures. Major differences were found in the tissues composing the capsule wall and attachment region, and at the tooth insertion. They can be used to characterize and distinguish the taxa studied. Results provide a useful tool for systematic research at the generic and specific levels within the Dicranales.