possum oak vs Quercus nigra

possum oak and Quercus nigra both are nouns.

Word	Noun	Adjective	Verb	Adverb
possum oak	Yes	No	No	No
Quercus nigra	Yes	No	No	No

As nouns, possum oak and Quercus nigra are synonyms defined as:

possum oak and Quercus nigra: relatively tall deciduous water oak of southeastern United States often cultivated as a shade tree; thrives in wet soil

Other synonyms of possum oak include water oak.

possum oak (noun)	Quercus nigra (noun)
relatively tall deciduous water oak of southeastern United States often cultivated as a shade tree; thrives in wet soil	relatively tall deciduous water oak of southeastern United States often cultivated as a shade tree; thrives in wet soil