regnellidium vs Regnellidium diphyllum

regnellidium and Regnellidium diphyllum both are nouns.

Word	Noun	Adjective	Verb	Adverb
regnellidium	Yes	No	No	No
Regnellidium diphyllum	Yes	No	No	No

As nouns, regnellidium and Regnellidium diphyllum are synonyms defined as:

regnellidium and Regnellidium diphyllum: small latex-containing aquatic fern of southern Brazil

regnellidium (noun)	Regnellidium diphyllum (noun)
small latex-containing aquatic fern of southern Brazil	small latex-containing aquatic fern of southern Brazil