Bad painting to include north European flower (6)
I believe the answer is:
danube
'flower' is the definition.
(European river - something which flows)
'bad painting to include north european' is the wordplay.
'bad painting' becomes 'daub' (term for an unprofessional painting).
'to include' indicates putting letters inside.
'north' becomes 'N' (abbreviation).
'european' becomes 'E' (abbreviation e.g. EU).
'daub' enclosing 'n' is 'danub'.
'danub'+'e'='DANUBE'
(Other definitions for danube that I've seen before include "River flowing from Black Forest to Black Sea" , "flower" , "South European river" , "5 down's river" , "Central European river" .)