Brier's inelegant sprawling (9)
I believe the answer is:
eglantine
'brier's' is the definition.
('eglantine' can be a synonym of 'brier')
'inelegant sprawling' is the wordplay.
'sprawling' indicates anagramming the letters.
'inelegant' anagrammed gives 'EGLANTINE'.
(Other definitions for eglantine that I've seen before include "Sweet brier" , "Inelegant (anag.); wild rose" , "Inelegant (anag) - plant" , "Milton's honeysuckle" , "Strangely inelegant scented plant" .)