Bulb flower (5)
I believe the answer is:
tulip
'bulb flower' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tulip that I've seen before include "Garden flower from bulb" , "Flowering bulb (from Amsterdam?)" , "It blooms in 11 down" , "(Dutch) bloom" , "Spring-blooming plant" .)