field-pea plant vs field pea

field-pea plant and field pea both are nouns.

Word	Noun	Adjective	Verb	Adverb
field-pea plant	Yes	No	No	No
field pea	Yes	No	No	No

As nouns, field-pea plant and field pea are synonyms defined as:

field-pea plant and field pea: variety of pea plant native to the Mediterranean region and North Africa and widely grown especially for forage

Other synonyms of field-pea plant include Austrian winter pea, Pisum arvense, Pisum sativum arvense.

field-pea plant (noun)	field pea (noun)
variety of pea plant native to the Mediterranean region and North Africa and widely grown especially for forage	coarse small-seeded pea often used as food when young and tender
	variety of pea plant native to the Mediterranean region and North Africa and widely grown especially for forage
	seed of the field pea plant