Long part of a flower (4)
I believe the answer is:
stem
'long part of a flower' 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 "Slender upright part, of flower or wineglass" , "Stanch" , "Slender upright part of wine glass" , "part of vegetable?" , "section of pipe" .)