Agony and ecstasy surrounding York's flower (9)
I believe the answer is:
hellebore
'flower' is the definition.
The answer and definition can be both plants as well as being singular nouns.
Maybe there's an association between them I don't understand?
'agony and ecstasy surrounding york's' is the wordplay.
'agony' becomes 'hell' (I can't justify this - if you can you should believe this answer much more).
'and' is a charade indicator (letters next to each other).
'ecstasy' becomes 'E' (informal term for the drug).
'surrounding' is an insertion indicator.
'york' becomes 'ebor' (abbreviation for Eboracum, Latin name for York).
'hell'+'e'='helle'
'helle' enclosing 'ebor' is 'HELLEBORE'.
Can you help me to learn more?
(Other definitions for hellebore that I've seen before include "In bed I grow" , "it comes out at Christmas" , "Flower of the lily family found in rebel hole" , "Winter-flowering plant" , "flowering plant" .)