Ceuthotheca is a monotypic genus. It is characterized by its strongly differentiated perichaetial leaves, immersed, ovoid capsules, and peristome that has well‑developed endostome segments. Although the immersed capsules of this genus are distinctive it may not be a character of generic importance within the family since both immersed and exserted capsules are found in Orthotrichum, Schlotheimia, and Macromitrium (M. brevisetum Mitt.). Ceuthotheca could be accommodated in Macromitrium as that genus is currently