671603-04 The Cardamine pratensis aggregate C. dentata, C. polemonioides
Geography: Circumboreal-polar.
Notes: The Cardamine pratensis aggregate is an intricate polyploid complex. The complexities are outlined in the classical studies of Lövkvist (1953, 1956, 1957), and several more problems are summarized and later sources referred by Jalas and Suominen (1994) and Lihova and Marhold (2003). An early molecular study is Franzke and Hurka (2000). The Northern (boreal and arctic) plants belong to three different groups assigned under the names C. dentata (or C. pratensis subsp. paludosa), C. polemonioides (or C. nymanii, or C. pratensis subsp. angustifolia), and C. pratensis (s. str., or subsp. pratensis). The three main questions for us are: (a) How many taxa can be recognized from the Arctic: one, two, or three? We enter two taxa but suspect that perhaps only one is present. (b) What rank to use for the taxa? Russians usually apply species, western and central Europeans and North Americans usually subspecies. We apply species as the taxa of this group may be allopolyploids combining different basal genomes and do not conform well with geographical or eco-geographical races. (c) Whether the North American arctic plants named as subsp. angustifolia and the Eurasian ones named as C. polemonioides or C. nymanii are the same? We consider them the same.
Different criteria may have been applied for separating between taxa in Russia and in western Europe. Doronkin (1994) mapped three species to be common throughout the majority of the arctic parts of Siberia, as C. pratensis, C. dentata, and C. nymanii. Other Russian treatments present similar pictures. This is improbable from the morphological criteria as they are applied in western Europe and North America. Cardamine pratensis s. str. L., Sp. Pl.: 656 (1753); lectotype (LINN): Europe. Herb. Linn. 835.15 (Khatri 1989: 92) is a mainly temperate European plant of moist, cultivated meadows and lawns, in Scandinavia never reaching or even approaching the Arctic. Cardamine dentata is a temperate to boreal European and western Siberian plant of swamps, water margins, and moist forests. It reaches boreal parts of northern Europe but has not been confidently recorded from arctic sites. We do not accept C. pratensis s. str. to reach the Arctic and perhaps not C. dentata either.
Elven and Carlsen: Cardamine pratensis s. lat. constitutes together with several European diploid and low polyploid species a very distinct, monophyletic clade in an ITS Cardamine phylogeny (Carlsen et al. 2009). The highly polyploid C. pratensis s. lat. seems to involve only taxa of this group as its putative parents and therefore seems to have a European origin.
Higher Taxa
- Cardamine [6716,genus]