Poison found in ruins of noble land (10)
I believe the answer is:
belladonna
'poison' is the definition.
(I know that belladonna is a type of atropine)
'ruins of noble land' is the wordplay.
I cannot quite understand how this works, but
'of' could be 'o' and 'o' is present in the answer.
an anagram of 'land' is 'ladn' which is present in the left over letters.
This may be the basis of the clue (or it may be nonsense).
'found in' is the link.
Can you help me to learn more?
(Other definitions for belladonna that I've seen before include "drug supplier" , "Drug made from deadly nightshade" , "Boy in Lebanon destroyed" , "plant" , "Deadly nightshade or atropine" .)