| Noccaea arctica (A.E. Porsild) Holub | |
| Publ. & Syn. | Thlaspi cochleariforme auct., non DC., Syst. Nat. 2: 381 (1821). - Noccaea cochleariforme auct., non (DC.) Á. Löve & D. Löve, Bot. Not. 128: 513 (1976). |
| Notes | Murray and Elven: The arctic plants in Eurasia and North America are very similar and should be included in one species, in spite of the indicated wide variation in ploidy levels. They have traditionally been named differently: Thlaspi cochleariforme in Russia and T. arcticum in North America. Hultén (1968b) proposed a merger under the former name. Our opinion is that the arctic plants differ significantly in morphology from the more southernly distributed Noccaea cochleariforme. Our solution is that all northern plants are kept apart from the southern ones and included in Noccaea arctica. The ploidy difference between North American and Siberian plants may be a ploidy series within a species, perhaps with the lowest ploidy level on the North American side, but the range from diploid to dodecaploid is rather large. |
| Chromosomes | (1) 14 (2x). - Alaska. - Dawe and Murray (1981c). (2) 28 (4x). - Siberia (Putorana). - Krogulevich (1976a, for "cochleariforme"). (3) 56 (8x). - Siberia (Taimyr). - Zhukova et al. (1973, for "cochleariforme"). (4) 84 (12x). - Far East (West Chukotka). - Zhukova and Petrovsky (1980, for "cochleariforme", two counts). |
| Geography | Asian (N) - amphi-Beringian: RUS SIB RFE ALA CAN. |
| Distribution | N = S AN = s D = R E = R UN = r Kh = r CW = r Tm = r [ key ] |
| Parent taxon | Noccaea Moench |
| PAF ID | 672401 |