male fern vs wood fern

male fern and wood fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
male fern	Yes	No	No	No
wood fern	Yes	No	No	No

As nouns, wood fern is a hypernym of male fern; that is, wood fern is a word with a broader meaning than male fern:

male fern: fern of North America and Europe whose rhizomes and stalks yield an oleoresin used to expel tapeworms
wood fern: any of various ferns of the genus Dryopteris

Other hypernyms of male fern include wood-fern, woodfern.

male fern (noun)	wood fern (noun)
fern of North America and Europe whose rhizomes and stalks yield an oleoresin used to expel tapeworms	any of various ferns of the genus Dryopteris