Popular van Gogh painting (6)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">popular van gogh painting</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for irises that I've seen before include "Subject for van Gogh" , "Expensive painting" , "Is sire in favour of flowers?" , "Coloured membranes in eyes, or showy flowers" , "blooms" .)