Petals collectively (7)
I believe the answer is:
corolla
'petals collectively' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for corolla that I've seen before include "part of plant" , "bit of a bloomer" , "Part of a flower" , "Internal whorl of a flower" , "Flower's petals collectively" .)