Mean to transplant one flower (7)
I believe the answer is:
anemone
'flower' is the definition.
(I know that anemone is a type of flower)
'mean to transplant one' is the wordplay.
'to transplant' indicates anagramming the letters.
'mean' anagrammed gives 'anem'.
'anem'+'one'='ANEMONE'
(Other definitions for anemone that I've seen before include "Brightly coloured flower or tube-shaped sea creature" , "Growth" , "Plant; sea creature" , "Tentacled sea dweller, flower" , "Plant; marine creature" .)