Lower Austria is the largest federal province in Austria. Being part of three biogeographical regions, it harbours a highly diverse bryophyte flora, which was well documented in historical reports. However, several places had been neglected. Bryological research has intensified during the last two decades. In this study, we present notable records of bryophytes made between 2017 and 2019: two taxa new to Austria (Cryphaea heteromalla, Orthodontium lineare); records of two species (Orthotrichum urnigerum, Riccia frostii), which have not been found for almost 150 years in Austria; seven more taxa, which are new to Lower Austria (Calliergon richardsonii, Dicranella grevilleana, Obtusifolium obtusum, Orthotrichum dentatum, Orthotrichum rogeri, Schljakovia kunzeana, Syntrichia subpapillosissima); and five species, supposedly extinct in Lower Austria, which have been reconfirmed. Furthermore, new localities for 28 species assessed as endangered or very rare in the Red Data list of Lower Austria are reported, many of which are new for one of the biogeographical regions of the federal province.
