Gymnocarpium robertianum vs northern oak fern

Gymnocarpium robertianum and northern oak fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gymnocarpium robertianum	Yes	No	No	No
northern oak fern	Yes	No	No	No

As nouns, Gymnocarpium robertianum and northern oak fern are synonyms defined as:

Gymnocarpium robertianum and northern oak fern: yellow-green fern of rocky areas of Northern Hemisphere

Other synonyms of Gymnocarpium robertianum include limestone fern.

Gymnocarpium robertianum (noun)	northern oak fern (noun)
yellow-green fern of rocky areas of Northern Hemisphere	yellow-green fern of rocky areas of Northern Hemisphere