The survey of the relevant literature dealing with Orthotrichum rogeri Brid. together with recent field investigations in France allow the author to give a complete account of the chorology, ecology and sociology of that taxon. Orthotrichum rogeri is a European species, confined in France to mountainous regions. This corticolous species thrives on a wide variety of phorophytes, in distinct vascular groupings, from shrubby patches with Sambucus racemosa and Salix caprea in old-growth mountainous forests, to anthropogenic Salix caprea stands. From a bryosociological perspective, Orthotrichum rogeri clearly fits within Ulotion crispae Barkman 1958, and most probably belongs to various associations. The management of the populations is discussed.