Panarctic Flora

630630 Oxytropis varians (Rydb.) K. Schum.

2n= (1) 16 (2x). - Alaska. - Dawe and Murray (1981c, two counts).
(2) 32 36 (4x). - Alaska. - Knaben (1968, for "gracilis"); Dawe and Murray (1981c).
(3) 48 (6x). - Alaska, Canada (NW, W). - Taylor and Taylor (1977, for "gracilis"); Elisens and Packer (1980, five counts).
(4) >60 64 (8x). - Alaska. - Johnson and Packer (1968, for "gracilis", according to Yurtsev most probably belonging to O. hyperborea); Löve and Löve (1982b, Manitoba, for "gracilis").
(5) 96 (12x). - Alaska, Canada. - At least four reports.

Geography: North American: ALA CAN.

Notes: Murray and Elven: Yurtsev (1986, PAF proposal, comments) characterized this section by regularly semi-verticillate leaflets. He assigned much taxonomic importance to this feature, whereas we (and many North American botanists before us) are more reluctant to see it as a feature present in only one evolutionary lineage.

Yurtsev: I consider sect. Baicalia a natural taxonomical unit with its diversity center in southeastern Siberia and central Asia. It consists mainly of steppe xerophytes with easily traced evolutionary lineages. The disjunctive distribution of Baicalia species in the tundra zone is of a relic nature (since tundra-steppe cryoxeric epochs). Parallel lineages from steppe plants to typical arctic ones are traced in eastern Siberia - Oxytropis scheludjakoviae -> O. schmorgunoviae -> O. sverdrupii -> O. wrangelii, with increased level of ploidy - and in North America - O. splendens -> O. bellii. The least advanced species (and morphotypes) in sect. Baicalia are close to sect. Orobia as secondary evolutionary lines marked by (semi)verticillate leaflets. An analogous situation occurs in sect. Gloeocephala (see below) where O. putoranica-O. uniflora (classic cushion plants) have derived from central Asian alpine steppe subsect. Oliganthae.

Murray and Elven: These suppositions - both about distinctness of species and about evolutionary pathways - should be investigated experimentally. As many of the species are exclusively Asian, we have not been able to evaluate them. We accept them provisionally, only with some modification on the North American side where we have some experience.