Van Gogh masterpiece (6)
I believe the answer is:
irises
'van gogh masterpiece' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for irises that I've seen before include "Eye membranes or showy flowers." , "Flags" , "Subject for van Gogh" , "Is sire in favour of flowers?" , "Coloured membranes in eyes, or showy flowers" .)