Panarctic Flora

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520108 Epilobium ciliatum Raf.

GBIF

Geography: Amphi-Pacific - North American & South American.

Notes: Hoch: We currently recognize this very complex group of plants (defined by the strong autapomorphy of ridged seeds) as a single species with the name Epilobium ciliatum Raf. According to Cronquist in Cronquist et al. (1997), there is no original material available for typification. As there is no doubt to what species Rafinesque was referring (there are only a couple of species of Epilobium in Pennsylvania and his description fits only one of them), this is the first available name for this extremely widespread species.

Within the complex, we recognize three subspecies: 1) Subspecies watsonii is restricted to a long narrow distribution along the Pacific coast of western North America; it rarely occurs more than 1-2 km from the coast, and to my knowledge this taxon has not been introduced elsewhere. 2) Subspecies glandulosum is considerably more widespread in cool montane-boreal regions throughout North America and eastern Asia, arguably introduced in Europe but nowhere nearly as weedy as the next Elven: this can be contested for western and northern Norway!. 3) Subspecies ciliatum is extremely widespread, occurring both as native and as an adventive weed throughout North America (including the Arctic), southern South America, and eastern Asia, and throughout Europe and Australasia as an introduced weed. Because this highly variable species predominantly self-pollinates, often establishing locally distinctive 'races', the multiple recent introductions in Europe have been interpreted as different species by Skvortsov. These are, however, only randomly selected and completely interfertile components of what is a more complex intergrading series of forms in North America.

Elven: This species is currently invasive in northern Europe in several 'morphs'. It is expanding northwards with an extraordinary speed in western and northern Fennoscandia and Iceland, has reached the Arctic in Iceland and may very soon do so in Scandinavia (if not there already). There is still some uncertainty as to how names are applied in Europe. We accept the American interpretation (see Hoch above) but a critical evaluation of some European material by North American experts would be nice for alignment of names, especially for delimitation of subsp. glandulosum from subsp. ciliatum. Subspecies ciliatum is the most common one in northern Europe but what we assign to subsp. glandulosum is quite common, too, especially in more oceanic areas. Northern European material assigned to subsp. glandulosum corresponds well with northwestern North American subsp. glandulosum.

Higher Taxa