Throw a lie about flower (7)
I believe the answer is:
lobelia
'flower' is the definition.
(I've seen this before)
'throw a lie about' is the wordplay.
'throw' becomes 'lob' (to lob something is to chuck or throw it).
'about' indicates anagramming the letters.
'a'+'lie'='alie'
'alie' anagrammed gives 'elia'.
'lob'+'elia'='LOBELIA'
(Other definitions for lobelia that I've seen before include "Bloomer" , "Common garden flower" , "One of the bellflower family grown as a bedding plant" , "I lob ale (anag)" , "Showy garden flower" .)