Bryoerythrophyllum is a genus of 28 species (Crosby et al. 2000). Although there are a few widely distributed species, the center of distribution for the genus seems to be in Asia and Latin America. Bryoerythrophyllum is distinguished by its distinctive, strong-red coloration, massive c-shaped papillae on the upper leaf cells and on the ventral surface of the costa, usually well-differentiated leaf bases, and a costa in cross-section that has two well-developed stereid bands as well as enlarged, ventral epidermal cells. Species of Bryoerythrophyllum often have dentate upper leaf margins, and although most species have short, erect peristome teeth, in some species the peristome is absent, rudimentary, or consists of long, spirally twisted teeth. The genus is similar to Didymodon or Barbula, indeed it is sometimes included within a broadly conceived Barbula (Smith 1978, Nyholm 1990). Zander (1993) distinguished it from Barbula by the combination of its reddish coloration, massive, crowded leaf papillae, and well-differentiated leaf bases.

The Latin American genera Mironia and Rhexophyllum are closely related to Bryoerythrophyllum. They differ from it essentially in having keeled leaves that are bistratose either at the margins (Mironia) or irregularly throughout the leaf lamina (Rhexophyllum). Rhexophyllum also differs from Bryoerythrophyllum in having a stem hyalodermis. The distinctions between these genera are blurred by the presence in Bryoerythrophyllum of a Mexican species (B. sharpii Zand.) that consistently has bistratose upper leaf cells as well as at least one species (e.g., B. ferruginascens (Stirt.) Giac.) that occasionally has bistratose patches in the upper parts of the leaves.