500726 Saxifraga hyperborea R. Br.
Distribution
Kanin - Pechora: Rare
Svalbard - Franz Joseph Land: Frequent
Polar Ural - Novaya Zemlya: Scattered
Yamal - Gydan: Scattered
Taimyr - Severnaya Zemlya: Frequent
Anabar - Onenyo: Scattered
Kharaulakh: Scattered
Yana - Kolyma: Scattered
West Chukotka: Frequent
Wrangel Island: Frequent
South Chukotka: Scattered
East Chukotka: Frequent
Western Alaska: Rare
Northern Alaska - Yukon: Frequent
Central Canada: Frequent
Hudson Bay - Labrador: Frequent
Ellesmere Island: Frequent
Western Greenland: Frequent
Eastern Greenland: Frequent
Polar desert: Frequent
Northern arctic Tundra: Frequent
Mid Arctic Tundra: Frequent
Southern Arcti Tundra: Frequent
Shrub Tundra: Scattered
Bordering boreal or alpine areas: Rare
- R. Br., Chlor. Melvill.: 16 (1823). Lectotype (BM!): Canada: the Northwest Territories?, Melville Island the Winter Harbour area. "25. Saxifraga hyperborea Flor. Melv." 1819-1820, leg. J. Ross (Webb and Gornall 1989: 148).
- Saxifraga rivularis var. purpurascens Lange, Consp. Fl. Groenland.: 62 (1880). Lectotype (C!): Greenland: "Groenlandia borealis: Disco, Quannesvit", 22. June 1871, leg. Th.M. Fries (Jørgensen and Elven in Jørgensen et al. 2006: 725).
- ?Saxifraga flexuosa Sternb., Revis. Saxifrag., Suppl. 2: 38 (1831). Lectotype (PR-463!): Russian Far East: East Chukotka, Lavrentiy Bay, left hand plant (Jørgensen and Elven in Jørgensen et al. 2006: 724). - ?Saxifraga rivularis var. flexuosa (Sternb.) Irmsch. in Engl., Pflanzenreich IV-117, 67: 282 (1916). - ?Saxifraga rivularis subsp. flexuosa (Sternb.) Gjærev., Kongel. Norske Vidensk. Selsk. Skr. (Trondheim) 1963, 4: 61 (1964).
2n=
26 (2x). - Europe (N), Siberia (N), Far East (N), Alaska, Canada, U.S.A.?, Greenland. - Numerous reports, partly for "flexuosa". Diploid in FCM, Jørgensen et al. (2006, Greenland, northeastern, northern, and northwestern Canada, western and southern Alaska, 28 plants from 20 populations, 15 "hyperborea" and 13 "flexuosa"); Guldahl et al. (2005, Svalbard, eastern Greenland, northern Canada, ten plants).
Not included: Reports of 2n = 26 (2x) from New Hampshire (Löve and Löve 1961d, 1965, 1966; Löve and Solbrig 1964b) and Iceland (Löve 1970a). The species is not known from Iceland and the report of a diploid from there is almost certainly erroneous. Also the White Mountains in New Hampshire is south of the range accepted for S. hyperborea by, e.g., Porsild and Cody (1980). However, the diploid White Mountains plants are enigmatic and not yet finally assigned to species (see Brouillet and Elvander 2009b: 144).
Geography: Circumpolar-alpine: NOR RUS SIB RFE ALA CAN GRL.
Notes: Zhmylev: Saxifraga hyperborea is a circumpolar arctic-alpine species differing from S. rivularis s. str. in tiny size, absence of underground runners, and larger hypanthium. These distinctions (except for the runners) are not always obvious.
Jørgensen and Elven: Additional differences are reported by Guldahl et al. (2005) and Jørgensen et al. (2006). The two species are distinctly different in several characters. Plants with transitional features are known and at least one of these is counted as a triploid (sterile) hybrid (Borgen and Elven 1983).
Saxifraga flexuosa has been considered an alpine parallel to the high-arctic S. hyperborea, e.g., tentatively by Webb and Gornall (1989: 285). It is reported from alpine parts of western North America north to the Brooks Range and the Richardson Mountains and also from similar parts of the Russian Far East north to East Chukotka (recorded as rare in East Chukotka, as scattered in West Alaska, and as frequent in North Alaska-Yukon). We have seen much material from both northeastern Asia and North America and has not seen any difference between Asian and American plants. Zhmylev (PAF proposal) identified all the diploid, more southern amphi-Beringian plants assigned to S. flexuosa as S. hyperborea. We found S. flexuosa to share its main diagnostic characters with high-arctic S. hyperborea but to differ slightly in a few, quantitative characters (e.g., longer pedicels). In comparative cultivation, S. flexuosa and S. hyperborea retained or rather strengthened their differences in general appearance. However, they were inseparable in molecular markers (AFLP). With the data now available, we follow Zhmylev's synonymization. Further investigations may show some racial differentiation between the high-arctic and the Pacific alpine plants.
The Cordilleran S. debilis Engelm. ex A. Gray, Proc. Acad. Nat. Sci. Philadelphia 15: 62 (1864), described from the Rocky Mountains in Wyoming, Colorado, and Utah, has been assigned to S. hyperborea as a subspecies: subsp. debilis (Engelm. ex A. Gray) Á. Löve, D. Löve & B.M. Kapoor, Arctic Alpine Res. 3: 151 (1971). It differs in several features from both S. hyperborea (including S. flexuosa) and S. rivularis and rather resembles S. sibirica and also Cordilleran S. cernua. Preliminary molecular data (Gabrielsen unpubl.) indicate relationship with both S. cernua and S. hyperborea and it may be parental in the evolution of parts of S. cernua. Saxifraga debilis is accepted by Brouillet and Elvander (2009b).
Higher Taxa
- Saxifraga [5007,genus]