641016 Potentilla uschakovii Jurtz.
Distribution
Wrangel Island: Rare
Mid Arctic Tundra: Rare
Southern Arcti Tundra: Rare
- Jurtz., Bot. Zhurn. 73: 1613 (1988). Holotype (LE): Russian Far East: Wrangel Island, "ad fontes fl. Somnitelnaja, 11 km ab ostio", 27. July 1986, leg. B.A. Yurtsev.
Geography: Asian Beringian: RFE.
Notes: Potentilla uschakovii is assumed to be a hybrid species from P. pulchella and P. subvahliana.
Yurtsev: The taxon is really rare (very local) in Wrangel Island but it is a population of very uniform individuals which cannot be joined with any other known taxon. We can remove the suspicion about hybrid origin. In contrast to all other presumed hybrid species of sect. Niveae x sect. Pensylvanicae, this taxon combines inflorescence and flowers of P. pulchella with the three-foliolate leaves of the Niveae type. To omit such an unusual plant would hardly be correct. Potentilla uschakovii differs from P. subvahliana (and others of the P. uniflora aggregate) also in petals obovate and smaller and in styles conical and viscid-verrucose in the lower third etc. In the intermontane depression of the headwater part of the Somnitelnaya River, it is abundant on the marginal parts of high terraces - zone of overlap between the ranges of P. subvahliana (from above, typical of Dryas integrifolia dry tundra) and of P. pulchella (from below, sparse herb continental high-arctic halophyte association where are the only localities in this vicinities of Poa hartzii and Roegneria villosa subsp. coerulea!). The overlap of P. pulchella and P. subvahliana is common in many other parts of Wrangel Island and the Canadian Arctic archipelago, but such a plant is restricted to only this particular headwater site where it is uniform and abundant.
Higher Taxa
- Potentilla [6410,genus]