Question came up after lunatic returned plant (6,4)
I believe the answer is:
damask rose
'plant' is the definition.
The answer is an example.
'question came up after lunatic returned' is the wordplay.
'question' becomes 'ask'.
'came up' becomes 'rose' (I've seen this before).
'after' means one lot of letters go next to another.
'lunatic' becomes 'mad' (I've seen this before).
'returned' is a reversal indicator.
'mad' backwards is 'dam'.
'ask'+'rose'='askrose'
'askrose' after 'dam' is 'DAMASK ROSE'.
(Other definitions for damask rose that I've seen before include "Sweet-scented flower yielding attar" , "hardy flower" , "bloomer" , "source of attar" .)