Mark of disgrace; part of a flower (6)
I believe the answer is:
stigma
This clue is a double definition.
'mark of disgrace' is the first definition.
(I've seen this before)
'part of a flower' is the second definition.
(I know this)
(Other definitions for stigma that I've seen before include "Disgraceful sign" , "Badge of shame" , "Mark of dishonour" , "evidence of nastiness?" , "Mark of shame or social disgrace" .)