Plant with scrap value finally scrapped (7)
I believe the answer is:
ragwort
'value finally scrapped' is the definition.
I can't judge whether this definition defines the answer.
'plant with scrap' is the wordplay.
'plant' becomes 'wort' (wort is a kind of plant).
'with' is a charade indicator (letters next to each other).
'scrap' becomes 'rag' (both can mean a piece of material).
'wort' put after 'rag' is 'RAGWORT'.
Can you help me to learn more?
(Other definitions for ragwort that I've seen before include "Widespread obnoxious weed" , "Plant toxic to livestock" , "Yellow flower, poisonous to cattle" , "Yellow-flowered weed" , "13 across toxic to livestock" .)