Plant publication about European duck (7)
I believe the answer is:
oregano
'plant' is the definition.
(oregano is a kind of plant)
'publication about european duck' is the wordplay.
'publication' becomes 'organ' (organ is a kind of publication**).
'about' indicates putting letters inside.
'european' becomes 'e' (abbreviation e.g. EU).
'duck' becomes 'o'.
'organ' enclosing 'e' is 'oregan'.
'oregan'+'o'='OREGANO'
(Other definitions for oregano that I've seen before include "Herb related to marjoram" , "herbal preparation" , "Sweet-smelling herb" , "Mediterranean herb" , "Type of herb" .)