Flower's support (4)
I believe the answer is:
stem
'flower's support' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stem that I've seen before include "'Stalk, shank (4)'" , "root" , "Slender upright part, of flower or glass" , "Peduncle" , "Stop the flow of, check" .)