| Metastevia Grashoff, 1975 |
| Metastevia hintonii Grashoff, 1975 |
| Mexerion G.L. Nesom, 1990 |
| Mexerion mexicanum G.L. Nesom, 1990 |
| Mexerion sarmentosum (Klatt) G.L. Nesom, 1990 |
| Mexianthus B.L. Rob., 1928 |
| Mexianthus mexicanus B.L. Rob., 1928 |
| Micrelium Forssk., 1775 |
| Microchaeta Nutt., 1841 |
| Microcoecia Hook. f., 1847 |
| Micropus L., 1753 |
| Micropus californicus Fisch. & C.A. Mey., 1835 |
| Micropus californicus var. californicus Fisch. & C.A. Mey., 1835 |
| Microseridinae Stebbins, 1953 |
| Microseris D. Don, 1832 |
| Microseris douglasii Sch. Bip., 1866 |
| Microseris elegans Greene ex A. Gray, 1884 |
| Microseris heterocarpa (Nutt.) K.L. Chambers, 1955 |
| Microseris lindleyi (DC.) A. Gray, 1883 |
| Microseris linearifolia (Nutt.) Sch. Bip., 1866 |