Droops on the stem (5)
I believe the answer is:
wilts
'droops on the stem' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for wilts that I've seen before include "Southern county" , "(Of plant) becomes limp" , "A county (abbr.); suffers from 1" , "part of the kingdom" , "Becomes limp; county" .)