scented fern vs boulder fern

scented fern and boulder fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
scented fern	Yes	No	No	No
boulder fern	Yes	No	No	No

As nouns, scented fern and boulder fern are synonyms defined as:

scented fern and boulder fern: fern of eastern North America with pale green fronds and an aroma like hay

Other synonyms of scented fern include Dennstaedtia punctilobula, hay-scented, hay-scented fern.

scented fern (noun)	boulder fern (noun)
fern of eastern North America with pale green fronds and an aroma like hay	fern of eastern North America with pale green fronds and an aroma like hay
common perennial aromatic herb native to Eurasia having buttonlike yellow flower heads and bitter-tasting pinnate leaves sometimes used medicinally
sweetly scented African fern with narrow bipinnate fronds