| Asplenium monanthes L., 1767 |
| Asplenium monodon Liebm., 1849 |
| Asplenium monteverdense Hook., 1860 |
| Asplenium muenchii A.R. Sm., 1975 |
| Asplenium munchii A.R. Sm., 1975 |
| Asplenium myapteron Fée, 1857 |
| Asplenium myriophyllum (Sw.) C. Presl, 1825 |
| Asplenium neglectum H. Karst., 1860 |
| Asplenium nesioticum Maxon, 1913 |
| Asplenium nigricans D.C. Eaton, 1873 |
| Asplenium nigripes (Fée) Hook., 1857 |
| Asplenium obesum Baker, 1867 |
| Asplenium obtusifolium L., 1753 |
| Asplenium obtusifolium var. riparium (Liebm.) Domin, 1929 |
| Asplenium obtusissimum Fée, 1852 |
| Asplenium oligosorum Mickel & Beitel, 1988 |
| Asplenium olivaceum A.R. Sm., 1975 |
| Asplenium onustum Christ, 1901 |
| Asplenium otites Link, 1833 |
| Asplenium palmeri Maxon, 1909 |