Killer plant devours outlaw close to cave (9)

I believe the answer is:

wolfsbane

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'killer plant' is the definition.
The definition and answer can be both plants as well as being singular nouns.
Perhaps there's a link between them I don't understand?

'devours outlaw close to cave' is the wordplay.
'devours' becomes 'wolfs' (I've seen this in another clue).
'outlaw' becomes 'ban' (banning is a kind of outlawing).
'close to' says to take the final letters (the close of something is the end).
The last letter of 'cave' is 'e'.
'wolfs'+'ban'+'e'='WOLFSBANE'

Can you help me to learn more?

I've seen this clue in The Independent.

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