pea vs common pea

pea and common pea both are nouns.

Word	Noun	Adjective	Verb	Adverb
pea	Yes	No	No	No
common pea	Yes	No	No	No

As nouns, common pea is a hyponym of pea; that is, common pea is a word with a more specific, narrower meaning than pea:

pea: a leguminous plant of the genus Pisum with small white flowers and long green pods containing edible green seeds
common pea: plant producing peas usually eaten fresh rather than dried

pea (noun)	common pea (noun)
seed of a pea plant used for food	plant producing peas usually eaten fresh rather than dried
a leguminous plant of the genus Pisum with small white flowers and long green pods containing edible green seeds
the fruit or seed of a pea plant