Panarctic Flora

641024 Potentilla beringensis Jurtz.

• Jurtz., Fl. Arct. URSS 9, 1: 317, 163 (1984). Holotype (LE): Russian Far East: East Chukotka, "Peninsulae Czukotskij pars extremiorientalis, litus septentrionalis sinu Laurentii prope pagum Laurentii", 02. July 1972, leg. N. Sekretareva, V. Razzhivin, and B. Yurtsev.

2n= 28 (4x). - Far East (East Chukotka). - Zhukova and Petrovsky (1985b).

Geography: Asian Beringian: RFE.

Notes: Elven and Murray: Potentilla beringensis is assumed to be a hybrid species from P. hyparctica and either P. pulchella (Yurtsev) or perhaps P. anachoretica (Soják 2004).

Yurtsev: Potentilla beringensis at St. Lawrence Bay has mostly ternate leaves with an admixture of shortly pinnate, semidigitate, or digitate ones. The plant well differs from species of sect. Pensylvanicae in its combination of characters, including large (up to 2 cm broad) corolla with broadly obcordate petals and greenish (not rubescent) stem. The leaves have deeply dissected leaflets (the segments are linear oblongate, obtusate, congested) and ovate stipules. The plant was found in one locality (in the vicinity of Lavrentiya village) with three small local populations on sandy beach and high terrace at the crest, in all three cases in forb-Leymus villosissimus meadow in quite natural vegetation. Many characters (including the poor development of crispate wool) permit to suggest the hypothesis of hybridogeneity with participation of P. hyparctica, common in all three sites. No species of sect. Pensylvanicae is present. Candidature of P. anachoretica is rejected owing to inappropriate morphology and ecology. There remains the candidature of P. pulchella with its modern (Holocene) disjunction between Wrangel Island and northern Alaska; sea coasts are one of its favourite site types. So, it is by no means a primary hybrid, rather a relict plant remaining in only one known locality.

Elven and Murray. Hybridization with stabilization between P. hyparctica and members of sect. Pensylvanicae is probable. Still, we need more evidence before this species can be fully accepted, especially as a hybrid species in the absence of any of the suggested parents from sect. Pensylvanicae: P. pulchella and P. anachoretica.