| Equisetaceae | ! |
Equisetum hyemale subsp. affine
| (Engelm.) Calder & Roy L. Taylor | Canad. J. Bot. 43(11): 1387 | 1965 |
| Equisetaceae | |
Equisetum hyemale var. affine
| (Engelm.) A.A. Eaton | Fern Bull. 11(4): 111–112 | 1903 |
| Equisetaceae | |
Equisetum hyemale subsp. affine x laevigatum
| | | ** |
| Equisetaceae | |
Equisetum hyemale subsp. affine x myriochaetum
| | | ** |
| Equisetaceae | * |
Equisetum hyemale var. californica
| Farw. | Mem. New York Bot. Gard. 6: 465 | 1916 |
| Equisetaceae | |
Equisetum hyemale var. californicum
| Milde | Verh. Zool.-Bot. Ges. Wien 12: 1264 | 1862 |
| Equisetaceae | |
Equisetum hyemale fo. drummondii
| M. Broun | | ** |
| Equisetaceae | |
Equisetum hyemale var. elatum
| (Engelm.) C.V. Morton | Leafl. W. Bot. 6(7): 156 | 1951 |
| Equisetaceae | ! |
Equisetum hyemale subsp. hyemale
| | | |
| Equisetaceae | |
Equisetum hyemale fo. intermedium
| Vict. | Contr. Lab. Bot. Univ. Montréal 9: 89 | 1927 |
| Equisetaceae | |
Equisetum hyemale var. intermedium
| A.A. Eaton | Fern Bull. 11: 108 | 1903 |
| Equisetaceae | |
Equisetum hyemale var. intermedium
| A.A. Eaton | Fern Bull. 10: 120 | 1902 |
| Equisetaceae | |
Equisetum hyemale var. jesupi
| Vict. | Contr. Lab. Bot. Univ. Montréal 9: 90 | 1927 |
| Equisetaceae | |
Equisetum hyemale var. komarovii
| (Iljin) W. Wang | | ** |
| Equisetaceae | |
Equisetum hyemale var. mackaii
| Newman | Phytologist 1: 305 | 1843 [1842] |
| Equisetaceae | |
Equisetum hyemale subsp. moorei
| Syme & N.E. Br. | | ** |
| Equisetaceae | |
Equisetum hyemale var. moorei
| Hook. & Arn. | | ** |
| Equisetaceae | |
Equisetum hyemale fo. polystachyum
| Prag. | List N. Amer. Pterid. 8: 26 | 1901 |
| Equisetaceae | |
Equisetum hyemale fo. proliferum
| Haberer | | ** |
| Equisetaceae | |
Equisetum hyemale fo. pseudohyemale
| | | ** |
| Equisetaceae | |
Equisetum hyemale var. pseudohyemale
| (Farw.) C.V. Morton | Ill. Fl. N. U.S. 1: 16 | 1952 |
| Equisetaceae | |
Equisetum hyemale fo. pumilum
| Vict. | Contr. Lab. Bot. Univ. Montréal 9: 89 | 1927 |
| Equisetaceae | |
Equisetum hyemale var. robustum
| (A. Braun ex Engelm.) A.A. Eaton | Fern Bull. 11: 75, 112 | 1903 |
| Equisetaceae | |
Equisetum hyemale var. suksdorfii
| A.A. Eaton | Fern Bull. 11: 110 | 1903 |
| Equisetaceae | |
Equisetum hyemale var. tenellum
| Lilj. | | ** |
| Equisetaceae | |
Equisetum hyemale fo. texanum
| M. Broun | | ** |
| Equisetaceae | |
Equisetum hyemale subsp. trachyodon
| A. Braun | Flora 22(20): 308 | 1839 |
| Equisetaceae | |
Equisetum hyemale subsp. variegatum
| (Schleich. ex F. Weber & D. Mohr) A. Braun | Flora 22(20): 308 | 1839 |
| Equisetaceae | |
Equisetum hyemale var. variegatum
| (Schleich. ex F. Weber & D. Mohr) Newman | Phytologist 1: 337 | 1842 |
| Equisetaceae | |
Equisetum hyemale var. x variegatum
| | | ** |