Plant credit note on wrong peer (7)
I believe the answer is:
creeper
'plant' is the definition.
(creeper is a kind of plant)
'credit note on wrong peer' is the wordplay.
'credit' becomes 'cr'.
'note' becomes 'e' (musical note**).
'on' is an insertion indicator.
'wrong' indicates anagramming the letters.
'peer' with letters rearranged gives 'eper'.
'e' put within 'eper' is 'eeper'.
'cr'+'eeper'='CREEPER'
(Other definitions for creeper that I've seen before include "Plant spreading along the ground or up walls" , "one going up the wall after 8 [STATE = VIRGINIA]" , "Ivy or Virginia, for example" , "Climbing-plant" , "Reptile" .)