Panarctic Flora

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672401 Noccaea arctica (A.E. Porsild) Holub

Distribution

Polar Ural - Novaya Zemlya: Rare
Taimyr - Severnaya Zemlya: Rare
Kharaulakh: Rare
West Chukotka: Rare
Northern Alaska - Yukon: Scattered
Southern Arcti Tundra: Rare
Shrub Tundra: Rare
Bordering boreal or alpine areas: Scattered

2n= (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.

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.

Higher Taxa