Panarctic Flora

672114 Draba corymbosa R. Br. ex DC.

• DC., Syst. Nat. 2: 342-343 (1821). Holotype (BM!): Canada: Nunavut, Bylot Island, Posesion Bay, leg. E. Sabine (see Mulligan 1974a: 792).
• Draba macrocarpa Adams, Nouv. Mém. Soc. Imp. Naturalistes Moscou 3: 249 (1834). Described from northern Yakutia (Siberia).
• Draba bellii Holm, Repert. Spec. Nov. Regni Veg. 3: 338 (1907). Described from Greenland.
• Draba barbata Pohle, Izv. Imp. Bot. Sada Petra Velikago 14: 467 (1914). Described from Siberia and North America.
• Draba kjellmanii Lid ex E. Ekman, Svensk Bot. Tidskr. 25: 478 (1931). Holotype (S!): European Russia: Novaya Zemlya, Kristovaja Guba, 1911, leg. S.J. Enander.
• ?Draba pohlei Tolm., Trudy Bot. Muz. 24: 272 (1932). Type (LE): Siberia: Taimyr, south coast of Taimyr Lake, peninsula Deptu-Molla 7438'N 10404'E, 25. July 1928, leg. A.I. Tolmachev.
• Draba alpina auct., non L. (1753).

2n= ca. 100-144 (ca. 14-18x). - Europe (N), Siberia (N), Far East (N), Canada, Greenland. - Several reports, partly for D. alpina and D. macrocarpa.
Not included: A report of 2n = ca. 80 (10x) from Wrangel Island (Zhukova and Petrovsky 1984, for D. macrocarpa). This number is otherwise unknown from D. corymbosa.

Geography: Circumpolar: NOR RUS SIB RFE ALA CAN GRL.

Notes: Draba corymbosa is a complex and high polyploid species or species aggregate shown by Brochmann et al. (1992 and other papers) to have arisen numerous times, probably from different parental combinations. Several species names are based on plants from different regions: D. macrocarpa (Siberia), D. bellii (Greenland), D. corymbosa (Canada), D. kjellmanii (European Russia), and D. pohlei (Siberia). Petrovsky commented that the five taxa put into the synonymy of D. corymbosa might be geographical races of a large aggregate. We suspect that the complicated morphological and evolutionary pattern may prevent any formal recognition of more than one species. Further study of morphology, geography, and molecular variation of these taxa might, however, justify additional taxa. According to Petrovsky, this is especially relevant for the plant considered by the Russians as D. kjellmanii, although it will probably be impossible to select a type for that name which makes it represent a new species (see below).

The application of D. corymbosa as a priority name has been disputed. Ekman rejected it because she identified the assumed (holo)type in BM as Cochlearia fenestrata R. Br. (= C. groenlandica L.). This rejection was unjustified. There are two sheets. One of them contains a very typical and well preserved Cochlearia and has two labels annotated by Brown - as Cochlearia fenestrata and as Draba corymbosa - the latter probably mounted by mistake. Another sheet, which Ekman probably did not see, contains a less well preserved but typical D. corymbosa in current usage. It was annotated as such by Brown and identified as holotype by Mulligan (1974a).

Three of the synonyms above have been considered quite recently as names for species different from D. corymbosa:

Draba barbata Pohle. - Petrovsky and Elven studied the available syntypes (LE). All or nearly all specimens in the original material conform morphologically to D. corymbosa as currently understood, and the protologue indicates that a lectotype should be chosen among these specimens. The recent application of the name is another matter. Even if parts of the LE material annotated as D. barbata correspond to D. corymbosa, others and larger parts of it (from northern Asia) resemble D. pilosa and may be part of or close to that species. This is the application of the name D. barbata for Siberia by Nikiforova (1994). Similar plants occur in northwestern North America.

Draba kjellmanii Lid ex E. Ekman. - This species was accepted as late as by Walters and Akeroyd (1993). The only available type material is a sheet containing an envelope with numerous plants, a mixture of D. corymbosa in the current usage (the majority of the plants), some specimens of either D. alpina or perhaps D. glacialis (see above), and one or two specimens of D. oxycarpa. Ekman's protologue is a composite based on this mixture. It is not possible to identify any specific element that fits the protologue very well. We have, arbitrarily, placed the name in the synonymy of D. corymbosa as the majority of the specimens in the envelope belongs to that species. This name will, in any case, be superfluous as all the elements in the original collection belong to previously described species. The later application of the name has been similarly confused. In the herbaria, the name has most often been applied for what we would now recognize as D. corymbosa, sometimes for D. oxycarpa.

Draba pohlei Tolm. - Tolmachev (1975b) reported this species from a few localities in Taimyr, Severnaya Zemlya, and on the Lyakhovski and Novosiberian islands, all within the geographical range of the polymorphic D. corymbosa. Petrovsky commented on a close affinity to D. corymbosa and it should probably be fully synonymized with that species. However, some material from Taimyr (type region, specimens in MHA!), annotated by Tolmachev as D. pohlei, probably belongs to D. glacialis. Inspection of original material and choice of a formal lectotype is needed before this name can be assigned with certainty. We provisionally include it under D. corymbosa.