Macleaya R. Brown

Macleaya is a genus of only two species, native in China and Japan. Both are cultivated as ornamentals in Europe. However, their hybrid is probably more widely grown than either (Turrill 1958, Cullen 1995d, Karlsson 2001, Stace 2010).

The identification of Macleaya in cultivation (and as an escape) is often critical. As a result of hybridization specific limits seem to have become more or less obscure. Belgian records are here referred to as Macleaya cordata but most records might represent M. xkewensis Turrill, its hybrid with M. microcarpa (Maxim.) Fedde (Turrill 1958). To our knowledge, the latter has not been recorded so far in the wild in Belgium (and seems rare in cultivation as well). It is a much smaller plant, not exceeding 100 cm (Zhang & Grey-Wilson 2008a).

Both species of Macleaya were initially described as members of the genus Bocconia Plum. ex L. and some authors still consider both as congeneric. The latter, however, is a related but distinct New World genus (Blattner & Kadereit 1999, Mabberley 2008).


Adolphi K., Keil P., Loos G.H. & Sumser H. (2004) Kurze Notizen zu Vorkommen der Mohngewächse Macleaya spec., Meconopsis cambrica und Papaver atlanticum. Flor. Rundbr. 38: 29-37.

Blattner F.R. & Kadereit J.W. (1999) Morphological evolution and ecological diversification of the forest-dwelling poppies (Papaveraceae: Chelidonioideae) as deduced from a molecular phylogeny of the ITS region. Pl. Syst. Evol. 219(3-4): 181-197. [available online at:]

Blunt W. (1976a) Poppycock: the plume poppy. Garden (London) 101(3): 150-151.

Cullen J. (1995d) Macleaya. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 4. Cambridge University Press, Cambridge: 116.

Hutchinson J. (1920) Bocconia and Macleaya. Kew Bull. 1920: 275-282.

Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.

Karlsson T. (2001) Papaveraceae. In: Jonsell B. (ed.), Flora Nordica, vol. 2. The Bergius Foundation, Stockholm: 340-368.

Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.

Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.

Turrill W.B. (1958) Macleaya kewensis (or M. x kewensis). Papaveraceae. Curtis’ Bot. Mag. 172: tab. 321.

Vent W. (1973) Beitrâge zur Kenntnis der Sippenstruktur der Gattungen Bocconia L. und Macleaya R. Br. (Papaveraceae). Acta Bot. Acad. Sci. Hung. 19(1-4): 385-391.

Zhang M.-L. & Grey-Wilson C. (2008a) Macleaya. In: Wu Z.-Y. & al. (eds.), Flora of China, vol. 7. Science Press, Beijing, China & Missouri Botanical Garden Press, Saint Louis, USA: 287-288. [available online at:]

Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith