gold fern vs fern

gold fern and fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
gold fern	Yes	No	No	No
fern	Yes	No	No	No

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

gold fern: fern of West Indies and South America having fronds with bright golden-yellow undersides
fern: any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

gold fern (noun)	fern (noun)
fern of West Indies and South America having fronds with bright golden-yellow undersides	any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores