Thorny plant becomes coated, they say (5)
I believe the answer is:
furze
This clue might be a double definition.
'thorny plant' is the first definition.
The answer and definition can be both plants as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'coated they say' is the second definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'becomes' is the link.
Can you help me to learn more?
(Other definitions for furze that I've seen before include "Dreamlike" , "Bushy growth" , "Spiny shrub" , "Another word for gorse" , "one shrub" .)