shell bean vs shell bean plant

shell bean and shell bean plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
shell bean	Yes	No	No	No
shell bean plant	Yes	No	No	No

As nouns, shell bean and shell bean plant are synonyms defined as:

shell bean and shell bean plant: a bean plant grown primarily for its edible seed rather than its pod

shell bean (noun)	shell bean plant (noun)
unripe beans removed from the pod before cooking	a bean plant grown primarily for its edible seed rather than its pod
a bean plant grown primarily for its edible seed rather than its pod