Panarctic Flora

671613 Cardamine blaisdellii Eastw.

• Eastw., Bot. Gaz. (Crawfordsville) 33: 146 (1902). Holotype (CAS): Alaska: the Seward Peninsula, Cape Nome, 1900, leg. F.E. Blaisdell. - Cardamine microphylla var. blaisdellii (Eastw.) Khatri, Feddes Repert. 101: 444 (1990). - Cardamine microphylla subsp. blaisdellii (Eastw.) D.F. Murray & S. Kelso, Rhodora 99: 40 (1997).
• Cardamine microphylla auct., non Adams (1817).
• Cardamine hyperborea auct., non O.E. Schulz (1903), p.p.

2n= (1) 28 (4x, x = 7). - Far East (N), Alaska. - Several reports, eight Russian ones for C. hyperborea.
(2) 42 (6x, x = 7). - Far East (N). - At least four reports.

Geography: Amphi-Beringian: RFE ALA CAN.

Notes: Elven, Carlsen, and M.H. Jørgensen: The morphological differences between the Lena River area Cardamine microphylla and the Chukotka and Bering Strait area C. blaisdellii (including C. hyperborea auct. ross.) are rather pronounced and seem to be constant. We follow Petrovsky in his opinion that C. microphylla and C. hyperborea auct. ross. are different species but conclude that C. hyperborea auct. ross. largely is conspecific with C. blaisdellii. Petrovsky commented that the tetraploid and hexaploid plants of his C. hyperborea are similar morphologically and that a highly polymorphic eastern population of C. hyperborea was the reason for an erroneous identification as C. microphylla s. str. and C. digitata.

The proposal to rank C. blaisdellii as a variety or subspecies of C. microphylla (Khatri 1990; Murray and Kelso 1997) is not supported. In the molecular data (Jørgensen et al. 2008), the three species - C. microphylla, C. blaisdellii, and C. digitata - appear as three nearly equidistant groups and C. digitata is positioned between the clusters of C. blaisdellii and C. microphylla in the PCO "room". Also morphologically the three species are about equidistant.

Petrovsky: The plants Schulz considered as C. hyperborea belong to the mini-aggregate C. blaisdellii, and the Chukotkan population should probably be evaluated for rank as subspecies. If we accept close affinity between C. blaisdellii and C. hyperborea but find significant difference between Asian and North American population, the Asian population can be treated as C. blaisdellii subsp. hyperborea.

Carlsen, M.H. Jørgensen, and Elven: The microsatellite data (Jørgensen et al. 2008) and morphology give another picture. We have included all available northeastern Asian chromosome vouchers (LE) of C. hyperborea auct. ross. in the analysis. The 2n = 28 plants group with American C. blaisdellii and are morphologically indistinguishable from the American plants. We therefore include 2n = 28 Asian C. hyperborea auct. ross. in C. blaisdellii. These plants are from West Chukotka. For the 2n = 42 plants, see C. "hyperborealis" below.