| Athyrium distentifolium Tausch ex Opiz | |
| Publ. & Syn. | Aspidium alpestre Hoppe, Neues Bot. Taschenb. 1805: 216. 1805. - Athyrium alpestre (Hoppe) Milde, Fil. Eur. 53: no. 2 (1867), non De Clairv. (1811). |
| Notes | See Fuchs (1974) and Kartesz and Gandhi (1991) for arguments why the often applied name Athyrium alpestre (Hoppe) Milde (1867) is inapplicable as a later homonym of A. alpestre De Clairv. (1811), the latter name referring to A. filix-femina. Athyrium distentifolium is a polymorphic species with a range of disjunct parts in the amphi-Atlantic and amphi-Pacific regions and in southern Siberia and central Asia. Hultén and Fries (1986: map 50) distinguished between var. distentifolium in all of Eurasia and Greenland, var. gaspense in northeastern North America (non-arctic), and var. americanum in northwestern North America. Devold and Scholander (1933) studied the southeastern Greenland material and clearly came to the "americanum" conclusion. Kato (1993) recognized all North American material, including plants from southern Greenland, as A. alpestre var. americanum, i.e., including both the widely allopatric races accepted by Hultén. He stated that the Japanese plants were close to var. americanum. The geographical pattern described by Kato needs some explanation. The taxa, also as proposed by Kato, are major races that await further morphological and perhaps molecular comparison. |
| Chromosomes | 80 (4x). - Canada, U.S.A. - Several reports. |
| Geography | North American (NE) - amphi-Atlantic - European & Asian (C) & amphi-Pacific - Cordilleran. |
| Parent taxon | Athyrium Roth |
| Child taxa |
Athyrium distentifolium subsp. americanum (Butters) Hultén Athyrium distentifolium subsp. distentifolium |
| PAF ID | 090202 |