Panarctic Flora

860104 Solidago multiradiata Aiton

• Aiton, Hort. Kew. 3: 218 (1789). Holotype (BM): Canada: Labrador, 1765, leg. Moravian missionaries, possibly Schloezer.

2n= (1) 18 (2x). - Canada, U.S.A. - Numerous reports.
(2) 36 (4x). - Far East (N), Alaska, Canada (W), U.S.A. (N, W). - Numerous reports, the Russian ones for S. compacta.
Not included: A report of 2n = 18 (2x) from Kamtchatka (Zhukova 1982, for S. multiradiata). Barkalov (1992) did not accept S. multiradiata from Kamtchatka where he mapped nearly all material as S. spiraefolia.

Geography: Amphi-Beringian (E) - North American (N).

Notes: Authors concerned with North America have either treated Solidago multiradiata collectively or with three northern varieties. Two of these are morphologically distinct and parapatric and are acceptable as races (or species). Subspecies multiradiata is distributed across the northern parts of North America from Newfoundland and Labrador (type area of the species) west to western Alaska but has not been identified in its strict meaning on the Asian side. Subspecies scopulorum is Cordilleran and reaches Alaska and the Yukon Territory but is not reported to reach the Arctic. The third race is amphi-Beringian and more problematic to characterize morphologically. On the American side, Hultén (1968a) recognized a small-grown var. arctica restricted to the Bering Strait and Sea coasts south to the Aleutian Islands, by him stated to differ only in being smaller and with longer upper stem leaves. On the Russian side, Rebristaya (1987a) and Korobkov (PAF proposal) have accepted it as a species, S. compacta, and these authors also include within this taxon more tall-grown plants that would have been included within subsp. multiradiata in western Alaska. Löve and Löve (1975a) accepted a diploid S. multiradiata s. str. and a tetraploid S. compacta (= var. arctica). There certainly are two ploidy levels but the division of the Löves is not convincing as seen from comments below. Semple and Cook (2006) did not recognize or discuss races in S. multiradiata.

Murray and Elven: We have compared plants from eastern Canada, where only S. multiflora s. str. should occur, from northwestern Canada and Alaska, and from Chukotka where only S. compacta should occur. We found little disjunction in the characters and did not find any clearly diagnostic differences (albeit much variation). We enter the two races provisionally as subspecies.