Return boat trip took in Mexican flowers (7)
I believe the answer is:
dahlias
'mexican flowers' is the definition.
'dahlias' can be an answer for 'flowers' (dahlia is a kind of flower). I'm not sure about the 'mexican' bit.
'return boat trip took' is the wordplay.
'return' says the letters should be written backwards.
'boat trip' becomes 'sail' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'took' becomes 'had' ('have' can be a synonym of 'take').
'sail'+'had'='sailhad'
'sailhad' reversed gives 'DAHLIAS'.
'in' is the link.
Can you help me to learn more?
(Other definitions for dahlias that I've seen before include "Might Ali dash for the flowers?" , "Flowers for Shia lad" , "bloomers" , "'Hid, alas, among the flowers (7)'" , "I had Al's fowers" .)