| Didymodon craspedophyllus Cardot, 1909 |
| Didymodon fallax (Hedw.) R.H. Zander, 1978 |
| Didymodon fallax var. fallax (Hedw.) R.H. Zander, 1978 |
| Didymodon fallax var. reflexus (Brid.) R.H. Zander, 1980 |
| Didymodon ferrugineus (Schimp. ex Besch.) M.O. Hill, 1982 |
| Didymodon filicaulis Cardot, 1910 |
| Didymodon fuscoviridis Cardot, 1909 |
| Didymodon hampei R.H. Zander, 1993 |
| Didymodon heribaudii Cardot, 1913 |
| Didymodon homomallus Hedw., 1801 |
| Didymodon incrassatolimbatus Cardot, 1909 |
| Didymodon killipii R.S. Williams, 1930 |
| Didymodon klotzschii Schwägr., 1842 |
| Didymodon laevigatus (Mitt.) R.H. Zander, 1978 |
| Didymodon mexicanus Besch., 1872 |
| Didymodon mexicanus var. subulatus Thér. & E.B. Bartram, 1926 |
| Didymodon michiganensis (Steere) Saito, 1975 |
| Didymodon novae-hispaniae J.A. Jiménez & M.J. Cano, 2021 |
| Didymodon patentifolius Thér., 1931 |
| Didymodon pichinchensis Taylor, 1848 |