Plant sprawling in tangle by base of tree (9)
I believe the answer is:
eglantine
'plant' is the definition.
The answer is an example.
'sprawling in tangle by base of tree' is the wordplay.
'sprawling' indicates anagramming the letters.
'by' means one lot of letters go next to another.
'base of' suggests the final letters.
The last letter of 'tree' is 'e'.
'in'+'tangle'='intangle'
'intangle' anagrammed gives 'eglantin'.
'eglantin'+'e'='EGLANTINE'
(Other definitions for eglantine that I've seen before include "Sweet brier" , "Inelegant (anag) - plant" , "Sweetbriar, inelegant in a way" , "Rose, growing wild" , "Strangely inelegant scented plant" .)