Caught bumpkin getting physical exercise with a plant (8)
I believe the answer is:
chickpea
'plant' is the definition.
(chickpea plant is a kind of plant)
'caught bumpkin getting physical exercise with a' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'bumpkin' becomes 'hick' (synonyms).
'getting' is a charade indicator (letters next to each other).
'physical exercise' becomes 'pe'.
'with' means one lot of letters go next to another.
'c'+'hick'+'pe'+'a'='CHICKPEA'
(Other definitions for chickpea that I've seen before include "Round yellowish seed, eaten as a pulse" , "Commonly eaten pulse" , "Edible yellowish seed, also called garbanzo" , "Mediterranean legume" , "hippy diet" .)