pericarp vs seed vessel

pericarp and seed vessel both are nouns.

Word	Noun	Adjective	Verb	Adverb
pericarp	Yes	No	No	No
seed vessel	Yes	No	No	No

As nouns, pericarp and seed vessel are synonyms defined as:

pericarp and seed vessel: the ripened and variously modified walls of a plant ovary

pericarp (noun)	seed vessel (noun)
the ripened and variously modified walls of a plant ovary	the ripened and variously modified walls of a plant ovary