Incapacitating plant left Biden without power (5)
I believe the answer is:
lotus
'incapacitating plant' is the definition.
(plant with incapacitating qualities in Greek myth)
'left biden without power' is the wordplay.
'left' becomes 'l' (common abbreviation).
'biden' becomes 'POTUS' (Joe Biden, President of the United States).
'without' suggests deleting specific letters.
'power' becomes 'p' (symbol in physics).
'potus' with 'p' taken out is 'otus'.
'l'+'otus'='LOTUS'
(Other definitions for lotus that I've seen before include "the indolent took for eating" , "Sacred waterlily" , "We forget having eaten this" , "Sacred flower" , "reason for indolence" .)