Plant beginning to bloom say given trophy (9)
I believe the answer is:
buttercup
'plant' is the definition.
(buttercup is a kind of plant)
'beginning to bloom say given trophy' is the wordplay.
'beginning to' indicates taking the first letters.
'say' becomes 'utter' (to utter something is to speak or say it).
'given' is a charade indicator (letters next to each other).
'trophy' becomes 'cup' (cup is a kind of trophy).
The initial letter of 'bloom' is 'b'.
'b'+'utter'+'cup'='BUTTERCUP'
(Other definitions for buttercup that I've seen before include "growth in the field" , "Meadow flower poisonous to cattle" , "weedy type" , "Rich yellow wild flower" , "Yellow-flowered grassland plant" .)