Panarctic Flora

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8104 Euphrasia L.

GBIF

Notes: Even if large parts of northern Euphrasia have been revised several times (Wettstein 1896; Jørgensen 1919; Pugsley 1930, 1933, 1936a; Sell and Yeo 1970; Yeo 1972, 1978; Gusarova 2005), many problems remain, not least when comparing across countries and regions.

In the boreal and arctic zones, Euphrasia is most varied in the Atlantic regions but only one species is reported with some confidence as amphi-Atlantic. This suggest very recent (postglacial) speciation. The amphi-Atlantic species has for some time been named as E. frigida, but this name belongs to another species and the amphi-Atlantic plant is now named E. wettsteinii. It occurs in northeastern Canada, Greenland, Iceland, Jan Mayen, Svalbard, and northern mainland Europe. In Greenland, E. wettsteinii co-occurs with probably two species, the true E. frigida and one yet undescribed. Three species are reported and partly described from the Arctic in northeastern North America (Sell and Yeo 1970): E. disjuncta, E. hudsoniana, and E. vinacea, centered on Hudson Bay (also indicating recent speciation). In addition, the European E. parviflora (as E. curta) is reported as adventive. Farther west it becomes fairly simple (Hultén 1968a, 1968b; Sell and Yeo 1970). Euphrasia subarctica replaces E. disjuncta in northwestern North America where it overlaps with the clearly different, amphi-Pacific E. mollis. The genus is rare in Siberia (Tzvelev 1980c; Ivanina PAF proposal; Gusarova 2005) but a plant resembling or the same as the Nordic E. hyperborea is reported, especially from Taimyr, and E. wettsteinii is reported to reach east to northwesternmost Siberia. In northern Europe (Kuzeneva 1966; Elven et al. 2005), the diversity increases westwards. Additional species reported and partly described from northern Fennoscandia are E. hyperborea, the very little known E. saamica, the widely European E. stricta which occurs as adventive (probably only with its northern var. tenuis), and E. salisburgensis which is not closely related to any other of the species that reach the Arctic. In northern Norway south of the arctic parts are found E. arctica, E. micrantha Rchb., and perhaps E. scottica Wettst.

A special case with regard to confusion is Iceland. Pugsley (1933) accepted numerous narrowly circumscribed species from there. More recently, Yeo (1972) accepted six species: E. arctica subsp. tenuis (= E. stricta var. tenuis or E. tenuis), E. calida Yeo as a non-arctic Icelandic endemic confined to geothermic sites, E. davidssonii Pugsley as a non-arctic Icelandic endemic, E. frigida auct. (= E. wettsteinii), E. ostenfeldii (Pugsley) Yeo as non-arctic in the British Isles, the Faeroes, and Iceland, and E. scottica as a non-arctic northwestern European species. He explicitly stated that E. arctica s. str., in spite of its name, is a non-arctic European species with type from the Faeroes. At about the same time, Löve (1970a) accepted three species from Iceland: E. brevipila (= E. stricta), E. curta (= E. parviflora) var. davidssonii (Pugsley) Á. Löve, and E. frigida auct. with subsp. frigida (= E. wettsteinii) and subsp. rotundifolia (Pugsley) Á. Löve, the last-mentioned considered by Yeo as the local Scottish E. rotundifolia Pugsley. The most recent survey by Kristinsson (2010) accepted two species for Iceland: E. arctica s. lat. (perhaps E. stricta, large-flowered and with short-stalked glands on leaves and calyx) and E. frigida auct. (= E. wettsteinii, small-flowered and eglandular). Based on field studies in recent years, this view may be too simple. A modern revision of the Icelandic Euphrasia is urgently needed.

For misapplications of the names E. arctica and E. frigida (in Greenland by Böcher et al. 1957, 1978, Feilberg 1984a, Bay 1992, and Fredskild 1996; in Svalbard by Rønning 1964, 1979, 1996), see those species and also E. wettsteinii below.

The systematics of Euphrasia is still insufficiently understood and there is an imbalance in our treatment. We have accepted the comparatively narrowly circumscribed species of Yeo for Canada but not for Europe. The species listed below belong - in the system of Wettstein, Pugsley, and Yeo - to subsect. Angustifoliae (E. salisburgensis) and subsect. Ciliatae (all others) with series Minutiflorae (E. disjuncta), series Parviflorae (E. frigida, E. mollis, E. vinacea, E. wettsteinii), series Nemorosae (E. curta/nemorosa), series Majoriflorae (E. hudsoniana, E. hyperborea, E. stricta, probably E. saamica) and series Grandiflorae (E. subarctica). We do not accept some features of this system, e.g., the separation of E. disjuncta and E. subarctica on two series and the inclusion of all Greenlandic plants in series Parviflorae.

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