American after fortune for plant (5)
I believe the answer is:
lotus
'plant' is the definition.
(lotus is a kind of plant)
'american after fortune' is the wordplay.
'american' becomes 'us'.
'after' is a charade indicator (letters next to each other).
'fortune' becomes 'lot' ('lot' can be a synonym of 'fortune').
'us' after 'lot' is 'LOTUS'.
'for' acts as a link.
(Other definitions for lotus that I've seen before include "Reason for forgetfulness" , "Cross-legged position adopted in yoga" , "Sacred symbol" , "In Greek mythology, a fruit which induces forgetfulness" , "We forget having eaten this" .)