Stories about origin of money trees (5)
I believe the answer is:
limes
'trees' is the definition.
(lime is a kind of tree)
'stories about origin of money' is the wordplay.
'stories' becomes 'lies' (to tell stories can mean to lie).
'about' is an insertion indicator.
'origin of' says to take the initial letters.
The initial letter of 'money' is 'm'.
'lies' going around 'm' is 'LIMES'.
(Other definitions for limes that I've seen before include "Citrus fruits" , "Pieces of fruit" , "boundary" , "Green fruit" , "Citrus trees" .)