Oxford museum compiled article on tree growth (9)
I believe the answer is:
ashmolean
'oxford museum' is the definition.
(I've seen this before)
'article on tree growth' is the wordplay.
'article' becomes 'an' (English indefinite article).
'on' is a charade indicator (letters next to each other).
'tree growth' becomes 'ashmole' (I can't justify this - if you can you should give a lot more credence to this answer).
'an' after 'ashmole' is 'ASHMOLEAN'.
'compiled' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for ashmolean that I've seen before include "Oxford institution" , "Oxford museum" .)