Panarctic Flora


580218 Salix sphenophylla A.K. Skvortsov

Geography: Asian (N/C) - amphi-Beringian - Cordilleran.

Notes: Argus, Elven, Murray, and Skvortsov: The ranges of the two proposed races of Salix sphenophylla are not clear. Skvortsov (1966) reported subsp. sphenophylla from Siberia (Anabar-Olenyok, Kharaulakh, Yana-Kolyma) and as questionable from Chukotka and western Alaska. He reported subsp. pseudotorulosa from Chukotka and western and northern Alaska. Hultén (1968a) mapped subsp. pseudotorulosa (as S. arctica subsp. torulosa) as Alaskan and northern Cordilleran. There is an overlap and reports of intermediates in Chukotka but Yurtsev commented that the major part of the collections from Chukotka well fits subsp. sphenophylla. Murray and Elven have compared specimens (ALA) from Chukotka and Alaska and find no consistent difference. Our current proposal is of a northern Siberian subsp. sphenophylla and an amphi-Beringian subsp. pseudotorulosa. We have sorted chromosome number reports accordingly. Skvortsov commented that subsp. pseudotorulosa could be an ecotype of S. arctica but the parapatric ranges count against that interpretation.

There is another possibility, suggested by Hultén (1968b): "It seems possible that this taxon i.e., subsp. [pseudotorulosa] represents the introgression between S. sphenophylla A. Skvorts. (S. cuneata Turcz. non Nutt.) with S. arctica". . Salix sphenophylla is reported to be diploid, whereas S. arctica is polyploid. Hybridization is probable where they meet and intermediate ploidy levels and morphology might be expected. Subspecies pseudotorulosa should be reexamined with this in view. However, nearly all chromosome reports of S. sphenophylla from Chukotka are of diploids.

Higher Taxa