Panarctic Flora

641029 Potentilla vulcanicola Juz.

• Juz., Bot. Mater. Gerb. Bot. Inst. Komarova Akad. Nauk SSSR 17: 222 (1955). Holotype (LE): Russian Far East: Kamtchatka, the Petropavlovsk area, 09. July 1930, leg. I. Zhirov and E. Sokovnina.

2n= 28 (4x). - Far East (South Chukotka). - Zhukova and Petrovsky (1985b, two counts). The only report specifically published as P. vulcanicola. It is probable that several reports of tetraploid P. uniflora belongs here, especially those from East Chukotka (see P. uniflora above).
Not included: A report of 2n = 14 (2x) from northeastern Asia (Sokolovskaya et al. 1985). Yurtsev (PAF proposal) reported only 2n = 28 for this species and the voucher behind the 2n = 14 count should be checked for identity.

Geography: Amphi-Beringian: RFE ALA CAN.

Notes: Yurtsev: Potentilla vulcanicola was described from Kamtchatka and proved to be widespread in South and East Chukotka and in Beringian Alaska. It is similar to P. uniflora s. str. in many characters except for being more robust with thinner and longer petioles and pedicels, leaf blades thin, with slightly protruding (below) lateral veins. The main diagnostic feature is regular presence of several stiff long hairs at the base and at the top of ovaries and nutlets (this character is rare, recorded usually in less advanced groups of Potentilla). Flowers are smaller, the epicalyx segments subacute, shorter than sepals. The upper parts of the petioles are laxly tomentose.

Elven and Murray: This is a major plant of Asian and American Beringia, reaching east of the Mackenzie River on the mainland and also the westernmost Canadian Arctic Archipelago in Banks and Victoria islands. Potentilla vulcanicola may perhaps replace P. uniflora entirely in easternmost Chukotka and in northwestern North America.