Flower cultivated by the Aztecs (6)
I believe the answer is:
dahlia
'flower cultivated by the aztecs' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dahlia that I've seen before include "Showy garden plant" , "Showy herbaceous perennial" , "Composite" , "Ali had (anag) - showy flower" , "Plant of the daisy family" .)