pondweed family vs family Potamogetonaceae

pondweed family and family Potamogetonaceae both are nouns.

Word	Noun	Adjective	Verb	Adverb
pondweed family	Yes	No	No	No
family Potamogetonaceae	Yes	No	No	No

As nouns, pondweed family and family Potamogetonaceae are synonyms defined as:

pondweed family and family Potamogetonaceae: plants that grow in ponds and slow streams; sometimes includes family Zosteraceae

Other synonyms of pondweed family include Potamogetonaceae.

pondweed family (noun)	family Potamogetonaceae (noun)
plants that grow in ponds and slow streams; sometimes includes family Zosteraceae	plants that grow in ponds and slow streams; sometimes includes family Zosteraceae