The moss Bryoerythrophyllum latinervium var. rotundatum X.L.Bai, D.M.Ren et L.Q.Yang is described as a new variety from Inner Mongolia, China. It is distinguished from Bryoerythrophyllum latinervium (Holmen) Fedosov et Ignatova by its rounded leaf apex. Light microscope photographs of the significant characters are provided and its distinctions from closely related taxa are discussed. A key to the Chinese species of Bryoerythrophyllum is provided.