Fodder plant lucerne (7)
I believe the answer is:
alfalfa
I believe this clue is a triple definition!
'fodder' is the first definition.
(alfalfa is a kind of fodder)
'plant' is the second definition.
(alfalfa is a kind of plant)
'lucerne' is the third definition.
(synonyms)
(Other definitions for alfalfa that I've seen before include "cattle feed" , "Plant used as fodder" , "A forage plant" , "odder plant" , "Lucerne, a fodder plant" .)