| Dryopteris expansa (C. Presl) FraserJenk. & Jermy | |
| Publ. & Syn. | Dryopteris austriaca auct., non Woyn. ex Schinz & Thell. (1915). |
| Notes | Tzvelev: North American Dryopteris expansa and European D. assimilis differ in, e.g., absence vs. presence of frond glands and in the shape and size of petiole scales. Elven: Comparing Eurasian and North American specimens, I agree that there is a difference in glands (but North American plants often have a few frond glands), but I do not find enough difference to justify two species. |
| Chromosomes | 82 (2x). - Europe, Canada, U.S.A. - Numerous reports. |
| Geography | Amphi-Pacific - North American (N) - amphi-Atlantic - European - Asian (W): ICE NOR RUS SIB RFE ALA CAN GRL. |
| Distribution | N = F AN = r GW = s D = R Ic = s E = F YG = b HL = r FN = f CE = r AW = s GE = r CW = r Tm = r KP = s [ key ] |
| Parent taxon | Dryopteris Adans. |
| PAF ID | 100101 |