As traditionally understood Meconopsis is a genus of about 50 species (Taylor 1934, Cobb 1989). All except one occur from the Himalayas to western China. One species is native to western Europe (Meconopsis cambrica). Rather numerous species are cultivated as ornamentals (see Ratter & Taylor 1995, Köhlein 2003, Jäger & al. 2008) but only few are fairly frequent in cultivation. Several websites are dedicated to the genus Meconopsis in cultivation, see for instance The Meconopsis Group (http://www.meconopsis.org) or Meconopsis World (http://meconopsisworld.com).
In recent times, the generic circumscription of Meconopsis came into question. Meconopsis cambrica, originally described as a species of Papaver (P. cambricum L.), is rather well separated from the Asian representatives of the genus, morphologically as well as geographically. It has a style rather than a stigmatic disc and seems more closely related to Papaver than to the remainder of Meconopsis. Recent molecular phylogenetic research confirmed this (Carolan & al. 2006, Xiao & Simpson 2017). Papaver was shown to be monophyletic only if Meconopsis cambrica (and the genus Roemeria) were included. Kadereit & al. (1997) already demonstrated that within Meconopsis two distinct lineages exist and that in its current circumscription it is neither monophyletic nor distinct from Papaver. Kadereit & al. (2011) recently confirmed that Meconopsis cambrica in fact belongs with Papaver. However, there are apparently no morphological similarities with extant species of Papaver and there is no obvious section or group of species with which to place Papaver cambrica. Still according to Kadereit & al. (2011) the basal lineage of Asian Meconopsis is better segregated as Cathcartia Hook. f. Generic limits of Meconopsis obviously are not yet stable. Therefore, and in accordance with the account in Euro+Med Plantbase, Meconopsis cambrica is here tentatively maintained in its traditional circumscription (which also is in agreement with the current concept of Meconopsis in horticulture).
A new infrageneric classification of the genus, based on molecular data, was recently proposed by Xiao & Simpson (2017).
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