Chorologie et écologie d'Orthotrichum rogeri Brid. en France

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.