Evergreen, white plant (9)
I believe the answer is:
hollyhock
'plant' is the definition.
The answer is an example.
'evergreen white' is the wordplay.
'evergreen' becomes 'holly' (I have seen 'Prickly evergreen ' mean 'holly' so perhaps 'evergreen' could also mean 'holly').
'white' becomes 'hock' (type of white wine).
'holly'+'hock'='HOLLYHOCK'
(Other definitions for hollyhock that I've seen before include "A bloomer" , "Tall country garden flower" , "Plant with stout, hairy stems and spiky flowers" , "blooming great" , "Christmas decoration" .)