| Croton millspaughii Standl., 1930 |
| Croton miquelensis A.M. Ferguson, 1901 |
| Croton miradorensis Müll. Arg., 1866 |
| Croton mohavensis (A.M. Ferguson) Tidestr., 1935 |
| Croton monanthogynus Michx., 1803 |
| Croton morifolius Willd., 1805 |
| Croton morifolius var. genuinus Müll. Arg., 1865 |
| Croton morifolius var. lanatus Müll. Arg., 1866 |
| Croton morifolius var. obtusifolius Müll. Arg., 1865 |
| Croton morifolius var. sphaerocarpus (Kunth) Müll. Arg., 1865 |
| Croton muelleri J.M. Coult., 1894 |
| Croton muricatus Nutt., 1837 |
| Croton neomexicanus Müll. Arg., 1865 |
| Croton nervosus A. Rich., 1850 |
| Croton nitens Sw., 1788 |
| Croton niveus Jacq., 1760 |
| Croton oerstedianus Müll. Arg., 1865 |
| Croton ortegae Standl., 1940 |
| Croton ortholobus Müll. Arg., 1872 |
| Croton ovalifolius Vahl, 1793 |