South Hejaz (SH) is the richest region in Saudi Arabia (SA) with Bryaceae, where 8 out of a total of 13 species have been recorded. In the present work, four Bryaceae species have been recorded for the first time from SH and one of them (Bryum radiculosum Brid.) is a new record to SA and to Arabian Peninsula (AP). This brings the total number of fully identified mosses known from SH to 79 and from SA to 123. In addition, the number of Bryaceae species known from AP increased to 22 species.
         An identification key for the recorded Bryaceae from SH and all data about the studied specimens (e.g. Localities of collection, habitats, latitudes, longitudes, and altitudes..…etc.) are provided. The current study presented a distribution of Bryaceae recorded from SH region in different phytogeographical regions in SA and AP countries, with spotlights on their floristic elements. The new record (Bryum radiculosum Brid.) is described, illustrated and some of its floristic  aspects are discussed.