pomme de prairie vs pomme blanche

pomme de prairie and pomme blanche both are nouns.

Word	Noun	Adjective	Verb	Adverb
pomme de prairie	Yes	No	No	No
pomme blanche	Yes	No	No	No

As nouns, pomme de prairie and pomme blanche are synonyms defined as:

pomme de prairie and pomme blanche: densely hairy perennial of central North America having edible tuberous roots

Other synonyms of pomme de prairie include breadroot, Indian breadroot, Psoralea esculenta.

pomme de prairie (noun)	pomme blanche (noun)
densely hairy perennial of central North America having edible tuberous roots	densely hairy perennial of central North America having edible tuberous roots