Patch of ground by American plant (5)
I believe the answer is:
lotus
'plant' is the definition.
(lotus is a kind of plant)
'patch of ground by american' is the wordplay.
'patch of ground' becomes 'lot'.
'by' is a charade indicator (letters next to each other).
'american' becomes 'us'.
'lot'+'us'='LOTUS'
(Other definitions for lotus that I've seen before include "Tropical water-lily" , "In myth, a plant whose fruit induced forgetfulness" , "A blooming" , "Sacred Egyptian water lily" , "Mythical fruit inducing state of luxurious dreaminess" .)