Is Welsh poppy, Meconopsis cambrica (L.) Vig. (Papaveraceae), truly a Meconopsis?

Since the nineteenth century, the western European endemic Meconopsis cambrica has been regarded as the only European representative of the genus Meconopsis Vig. This genus, which is otherwise restricted to the Himalayas, differs from Papaver in having a style rather than a stigmatic disc. A phylogenetic reconstruction using 65 internal transcribed spacer sequences of 62 taxa of Old World Papaveroideae and three outgroup taxa shows that M. cambrica is not the closest relative of the remainder of Meconopsis but rather the closest sampled relative of Papaver s.str. This is consistent with morphological evidence which suggests that the style evolved independently in M. cambrica from a Papaver-like ancestor. We suggest that Meconopsis cambrica should revert to its former name, Papaver cambricum L. We also suggest that: (1) the Arctic-montane species of Papaver sect. Meconella need to be placed in their own genus; (2) Papaver sect. Argemonidium (including P. argemone and P. hybridum) should be included in Roemeria Medik.; and (3) the basal lineage of Asian Meconopsis needs to be treated as an independent genus, Cathcartia Hook.f. As Meconopsis cambrica is the type of Meconopsis, conservation of Meconopsis Vig. with a different type is required to avoid further nomenclatural changes. The evolutionary history of M. cambrica is briefly discussed.