boulder fern vs hay-scented

boulder fern and hay-scented both are nouns.

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

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

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

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

boulder fern (noun)	hay-scented (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