| Cassia leiophylla var. pubescens Benth., 1871 |
| Cassia leptadenia Greenm., 1905 |
| Cassia leptadenia var. jaliscensis Greenm., 1905 |
| Cassia leptadenia var. mensalis Greenm., 1905 |
| Cassia leptocarpa Benth., 1849 |
| Cassia leptocarpa var. hirsuta Benth., 1871 |
| Cassia liebmannii Benth., 1871 |
| Cassia lindheimeriana Scheele, 1848 |
| Cassia longicoma Greenm., 1903 |
| Cassia longisiliqua L. f., 1781 |
| Cassia lutescens G. Don, 1832 |
| Cassia macdougaliana Rose, 1909 |
| 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 |