Buck embraces Penny in tree (5)
I believe the answer is:
maple
'tree' is the definition.
(maple is a kind of tree)
'buck embraces penny' is the wordplay.
'buck' becomes 'male' (I can't justify this - if you can you should believe this answer much more).
'embraces' is an insertion indicator.
'penny' becomes 'p' (short for pence).
'male' placed around 'p' is 'MAPLE'.
'in' is the link.
Can you help me to learn more?
(Other definitions for maple that I've seen before include "Syrup-producing tree" , "Tree; sauce" , "Tree associated with Canada" , "Tree whose leaf features on the flag of Canada" , "Tree: its leaf the Canadian emblem" .)