Name a flower (5)
I believe the answer is:
calla
'flower' is the definition.
(calla is a kind of flower)
'name a' is the wordplay.
'name' becomes 'call' (to call them someone something is to name them).
'call'+'a'='CALLA'
(Other definitions for calla that I've seen before include "Form of lily" , "South African plant" , "Variety of lily" .)