| Petasites frigidus subsp. nivalis (Greene) Cody | |
| Publ. & Syn. | Petasites hyperboreus Rydb., N. Amer. Fl. 34: 312 (1927). Holotype (NY): Canada: British Columbia, second summit west of Skagit River, 22. July 1905, leg. J.M. Macoun 76,977. |
| Notes | The majority of Russian authors have not accepted subsp. nivalis from northeastern Asia but plants indistinguishable from Alaskan ones of that subspecies are frequent, at least in East Chukotka. Subspecies nivalis is intermediate in most features between subsp. frigidus and subsp. palmatus but mainly occurs outside the range of subsp. palmatus in northwestern North America and northeastern Asia. Note that its type is from far south of the acknowledged range of subsp. frigidus. The synonymy between Petasites nivalis Greene (Washington) and P. hyperboreus Rydb. (British Columbia) should perhaps be reconsidered; the name subsp. nivalis may not be the correct one for the Beringian plant. Bayer et al. (2006) synonymized P. hyperboreus/nivalis with their var. frigidus. The nearly smooth transition between these in the northwestern North American material justifies that treatment (but in our concept as subspecies). However, the Beringian plants with deeply lobed leaves differ appreciably from the Siberian and northern European ones, i.e., from the major parts of the species including the type. |
| Chromosomes | (1) 56 60 (6x). - Europe (N), Russia (N), Siberia (N, S), Far East (N), Alaska, Canada. - Numerous reports. (2) 80 (8x). - Far East (West Chukotka). - Zhukova and Petrovsky (1976). |
| Geography | Asian (N) - amphi-Beringian - Cordilleran: RFE ALA CAN. |
| Distribution | N = F AN = s D = S E = F CE = s AW = s [ key ] |
| Parent taxon | Petasites frigidus (L.) Fr. |
| PAF ID | 862403b |