| Cassia macropoda (Standl.) Standl., 1929 |
| Cassia manzanilloana Rose, 1895 |
| Cassia maritima Willd. ex Vogel, 1837 |
| Cassia mensarum Ant. Molina, 1951 |
| Cassia mensicola H.S. Irwin & Barneby, 1975 |
| Cassia mexicana Jacq., 1797 |
| Cassia mexicana var. grandiflora Benth., 1871 |
| Cassia monozyx H.S. Irwin & Barneby, 1975 |
| Cassia morelensis Greenm., 1903 |
| Cassia moschata Kunth, 1824 |
| Cassia multiflora M. Martens & Galeotti, 1843 |
| Cassia multifoliolata Paul G. Wilson, 1958 |
| Cassia multiglandulosa Jacq., 1783 |
| Cassia multijuga Rich., 1792 |
| Cassia nelsonii Rose, 1897 |
| Cassia nicaraguensis Benth., 1871 |
| Cassia nictitans L., 1753 |
| Cassia nutans Collad., 1816 |
| Cassia obtusifolia L., 1753 |
| Cassia occidentalis L., 1753 |