Bank containing a very fragrant plant (8)
I believe the answer is:
lavender
'fragrant plant' is the definition.
(I've seen this before)
'bank containing a very' is the wordplay.
'bank' becomes 'lender'.
'containing' indicates putting letters inside.
'a very' becomes 'av' (I've seen this in other clues).
'lender' enclosing 'av' is 'LAVENDER'.
(Other definitions for lavender that I've seen before include "Plant used in perfumery" , "Light bluish-purple" , "Shrub with fragrant purple flowers, used to scent linen" , "Fragrant purple flower used to scent linen etc" , "Plant with aromatic purple flowers" .)