Tree in lime, leaning backwards (5)
I believe the answer is:
elemi
'tree' is the definition.
(tree from which elemi oil is obtained)
'in lime leaning backwards' is the wordplay.
'in' indicates the answer is hidden within the clue.
'backwards' is a reversal indicator.
'imele' is hidden within 'lime leaning'.
'imele' reversed gives 'ELEMI'.
(Other definitions for elemi that I've seen before include "Extract" , "Fragrant tree resin used as incense - I'm Lee (anag)" , "aromatic resin" , "Fragrant resin used as incense - Emile (anag)" , "Oleoresin" .)