Flowers had Lisa in pieces (7)
I believe the answer is:
dahlias
'flowers' is the definition.
(I know this)
'had lisa in pieces' is the wordplay.
'in pieces' indicates an anagram.
'had'+'lisa'='hadlisa'
'hadlisa' anagrammed gives 'DAHLIAS'.
(Other definitions for dahlias that I've seen before include "bloomers" , "I had Al's fowers" , "Tuberous garden plants" , "'Hid, alas, among the flowers (7)'" , "Herbaceous perennial plants of a Mexican genus" .)