The moss Didymodon tectorum (C. Müll.) Saito of Asia is newly reported for North America based on specimens previously reported as Didymodon reedii Robins. (a new synonym) and Didymodon brachyphyllus (Sull.) Zander, which remains a good species. A key to species of the Didymodon vinealis complex in North America is presented. Didymodon tectorum and D. brachyphyllus are described and illustrated and their North American distribution is mapped. The problem of the first valid publication of Barbula brachyphylla is briefly discussed. Barbula ferrinervis C. Müll., hom. illeg. (= B. feruginervis Broth.) is reduced to synonymy with Barbula indica (Hook.) Spreng. var. indica.