| Melanthiaceae | |
Trillium undulatum fo. cleavelandicum
| (Alph. Wood) Fernald | Rhodora 45: 517 | 1943 |
| Melanthiaceae | |
Trillium undulatum fo. enotatum
| Patrick | Rhodora 87: 157–158 | 1985 |
| Melanthiaceae | |
Trillium undulatum fo. polymerum
| Vict. ex Louis-Marie | Rev. Oka Agron. Inst. Agric. 14: 152 | 1940 |
| Melanthiaceae | |
Trillium undulatum fo. striatum
| Louis-Marie | Rev. Oka Agron. Inst. Agric. 14: 152 | 1940 |
| Melanthiaceae | |
Trillium undulatum fo. undulatum
| | | |