Gymnocarpium robertianum vs limestone fern

Gymnocarpium robertianum and limestone fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gymnocarpium robertianum	Yes	No	No	No
limestone fern	Yes	No	No	No

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

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

Other synonyms of Gymnocarpium robertianum include northern oak fern.

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