| Osmundaceae | |
Osmunda cinnamomea fo. angustata
| Clute | Fern Bull. 17: 12 | 1909 |
| Osmundaceae | |
Osmunda cinnamomea subsp. asiatica
| (Fernald) Fraser-Jenk. | New Sp. Syndr. Indian Pteridol. 185 | 1997 |
| Osmundaceae | |
Osmunda cinnamomea var. asiatica
| Fernald | Rhodora 32(376): 75–76 | 1930 |
| Osmundaceae | |
Osmunda cinnamomea fo. auriculata
| (Hopkins) Kittr. | Connecticut State Geol. Surv. Bull. 48: 12 | 1931 |
| Osmundaceae | |
Osmunda cinnamomea var. auriculata
| Hopkins | Amer. Fern J. 1: 100 | 1911 |
| Osmundaceae | |
Osmunda cinnamomea fo. bipinnatifida
| Clute | Fern Bull. 14: 15 | 1906 |
| Osmundaceae | |
Osmunda cinnamomea fo. cinnamomea
| | | |
| Osmundaceae | |
Osmunda cinnamomea var. cinnamomea
| | | |
| Osmundaceae | |
Osmunda cinnamomea fo. cornucopiaefolia
| Clute | Fern Bull. 16: 109 | 1909 |
| Osmundaceae | |
Osmunda cinnamomea var. fokienense
| Copel. | Philipp. J. Sci. 4(1): 16 | 1909 |
| Osmundaceae | |
Osmunda cinnamomea fo. frondosa
| (Torr. & A. Gray) Britton | Cat. Pl. New Jersey 312 | 1890 |
| Osmundaceae | |
Osmunda cinnamomea fo. frondosa
| Torr. & A. Gray | Annual Rep. State Geol. Surv. New York 4: 196 | 1840 |
| Osmundaceae | |
Osmunda cinnamomea var. glandulosa
| Waters | Fern Bull. 10: 21 | 1902 |
| Osmundaceae | |
Osmunda cinnamomea var. imbricata
| (Kunze) Milde | Monogr. Osmund. 95 | 1868 |
| Osmundaceae | |
Osmunda cinnamomea fo. incisa
| J.W.Huntington | Fern Bull. 7: 12 | 1899 |
| Osmundaceae | |
Osmunda cinnamomea fo. latipinnula
| S.F. Blake | Rhodora 15(177): 155 | 1913 |