500727b Saxifraga rivularis subsp. arctolitoralis (Jurtz. & V.V. Petrovsky) M.H. Jørg. & Elven
Distribution
West Chukotka: Scattered
Wrangel Island: Rare
East Chukotka: Scattered
Western Alaska: Rare
Northern Alaska - Yukon: Scattered
Central Canada: Rare
Hudson Bay - Labrador: Scattered
Ellesmere Island: Rare
Western Greenland: Scattered
Eastern Greenland: Rare
Mid Arctic Tundra: Rare
Southern Arcti Tundra: Scattered
Shrub Tundra: Scattered
- M.H. Jørg. & Elven, Syst. Bot. 31: 726 (2006). - Saxifraga arctolitoralis Jurtz. & V.V. Petrovsky, Bot. Zhurn. 66: 1045 (1981). Holotype (LE!): Russian Far East: East Chukotka, "Paeninsula Tschuktschorum pars australi-orientalis, litus boreali-occidentalis freti Senjavini, inter ostia fl. Chutenreczchenveem et fl. Kurgyveem", 19. Aug. 1978, leg. B.A. Yurtsev S-78-1.
2n=
ca. 48 52 (4x). - Far East (N), Alaska. - Several reports, mainly for S. rivularis.
Geography: Amphi-Beringian - North American (N): RFE ALA CAN GRL.
Notes: Zhmylev: Saxifraga arctolitoralis is an arctic species known with certainty only from Wrangel Island and East Chukotka but there are chromosome number reports also from West Chukotka and is probably a halophytic race of S. hyperborea from which it differs in chromosome number (Yurtsev 1984a; Zhukova and Petrovsky 1987a).
Jørgensen and Elven: We studied the material available in LE in 2003 and found subsp. arctolitoralis to be consistently different from S. hyperborea in regular occurrence of short stout underground runners, in hypanthium shape and size, and in coloration, and also different from S. rivularis s. str. but to a lesser degree. Plants collected in 2001 on the Seward Peninsula in western Alaska shared these characters of subsp. arctolitoralis, grouped with the amphi-Atlantic S. rivularis in the molecular analyses, proved to be tetraploid, and confirmed the subspecies also from the North American side. A subsequent revision of Alaskan material (by Elven in ALA, 2003) proved subsp. arctolitoralis with distinct runners and characteristic hypanthium etc. to be widespread along the coasts of northwestern and northern Alaska (e.g., in Barrow, also collected in several places there in 2005 by Elven and Solstad). Bennett (in comment, ALA, O) has documented subsp. arctolitoralis into the Yukon Territory and the Northwest Territories east to the western side of the Mackenzie River Delta. Plants conforming to subsp. arctolitoralis in morphology are also seen from Boothia Peninsula farther east in Canada (TROM), and plants conforming in both morphology and molecules from eastern Canada (Hudson Bay, Ungava-Labrador, Baffin Island), western Greenland (north to Thule), and at least two places in eastern Greenland (Westergaard et al. in print). The tetraploid chromosome number reported by Packer and McPherson (1974) from Barrow in northern Alaska certainly belongs to this taxon.
Higher Taxa
- Saxifraga rivularis [500727,species]