672126 Draba arctica J. Vahl
- J. Vahl, Fl. Dan. 13, 39: t. 2294 (1840). Described from Greenland and from Svalbard (Norway). Suitable syntypes are available from Svalbard (C, O!, S!). See notes.
Geography: Probably amphi-Atlantic.
Notes: Type. - Elven: The choice of type of the name Draba arctica should aim to preserve current usage and to follow the intentions of J. Vahl, that is, as a species different from D. cinerea. Böcher (1966a: 14) proposed the following material: Svalbard: Bellsound, 1838-1839, J. Vahl (C, O, S), "all three specimens serving as lectotypes", which means that he did not effectively designate a lectotype. The original material includes, in addition, specimens from Greenland and the illustration in Flora Danica. The Vahl specimens from Svalbard in O are well preserved, belongs to D. arctica, and we consider each of them suitable as lectotype. In S, one sheet is from Svalbard: "Spitsbergen. misit auctor" (J. Vahl). This is a clear D. arctica in our concept and would be suitable as lectotype. The second sheet contains three specimens, the two to the left from Svalbard ("Spitsbergen", D. arctica), the one to the right from Greenland (D. cinerea). We have not studied the Copenhagen sheet(s). Böcher stated that the Flora Danica illustration is a composite based on a combination of features from Svalbard ("arctica") and Greenland ("cinerea") plants. It should therefore not be considered suitable as lectotype. To confirm current usage and follow Vahl's intention, one should follow Böcher's suggestion and choose one of Vahl's nearly identical Svalbard (Bellsund) specimens as lectotype of D. arctica.
Ploidy level, range, and variation. - Petrovsky, Murray, and Elven: Draba cinerea and D. arctica are rather clearly different morphologically in the North Atlantic regions and in ploidy levels as hexaploid vs. decaploid (Böcher 1966a; Brochmann et al. 1992, 1993; Andersen et al. 1999; Andersen 2003). They also differ rather clearly in molecular markers (Brochmann et al. 1992, 1993; Andersen et al. 1999; Andersen 2003). Draba cinerea is comparatively southern in these regions. It occurs in southern and central Greenland but not in the north where it is replaced by D. arctica, D. oblongata, and D. arctogena. In northwestern Europe, it is restricted to a few, small and isolated populations in the northern boreal parts of the mainland (northern Norway, northern Finland, Karelia) and is replaced by D. arctica in Svalbard. The situation outside the North Atlantic regions is unresolved. In recent decades, D. arctica has been accepted also from northeastern European Russia and Siberia, but in North America it was still included by implication in D. cinerea by Porsild and Cody (1980), Rollins (1993), and Cody (1996). Petrovsky found it difficult to draw a clear line between D. arctica and D. cinerea in Siberian material, Elven and Murray found the same for Alaska and northwestern Canada (ALA). For Canada, Elven found "typical" D. arctica (i.e., as in Greenland and Svalbard) to be present in the northeastern parts (mainly on Ellesmere Island, CAN and DAO) but much more problematic to identify in the material from farther west. In addition, there is a lack of reliable reports of decaploids from plants of this aggregate from northwestern North America (and from Russia). Decaploid D. arctica may therefore be amphi-Atlantic only and we have recorded it as such in the distribution table.
Draba arctica is reported (see Böcher 1966a) with two races: subsp. arctica and subsp. ostenfeldii, both recorded as Atlantic. The plant published as D. ovibovina occurs within the range of D. arctica and seems to belong within one of its races. We have accepted the Greenland subsp. ostenfeldii as described and accepted by Ekman and Böcher. There are consistent morphological differences between subsp. ostenfeldii and D. arctica s. str. that may justify treatment as two species (Böcher 1966a; Andersen et al. 1999; Andersen 2003). They are sympatric and both are decaploid. The epithet "ostenfeldii" is, however, inapplicable for a species due to homonymy. If var. ovibovina is included in subsp. ostenfeldii, the name D. ovibovina (E. Ekman) E. Ekman 1941 will probably have priority for a species.
Higher Taxa
- Draba [6721,genus]