Deliver Ben amphora containing plant (7)
I believe the answer is:
verbena
'plant' is the definition.
(verbena is a kind of plant)
'deliver ben amphora containing' is the wordplay.
'containing' indicates the answer is hidden within the clue.
'VERBENA' can be found hidden inside 'deliver ben amphora'.
(Other definitions for verbena that I've seen before include "Vervain (plant)" , "Garden plant" , "Herbaceous plant" , "Ornamental plant with showy flowers" , "Ornamental pant" .)