Christmas green vs lycopod

Christmas green and lycopod both are nouns.

Word	Noun	Adjective	Verb	Adverb
Christmas green	Yes	No	No	No
lycopod	Yes	No	No	No

As nouns, lycopod is a hypernym of Christmas green; that is, lycopod is a word with a broader meaning than Christmas green:

Christmas green: any of several club mosses having long creeping stems and erect branches
lycopod: primitive evergreen moss-like plant with spores in club-shaped strobiles

Other hypernyms of Christmas green include club-moss, club moss.

Christmas green (noun)	lycopod (noun)
any of several club mosses having long creeping stems and erect branches	primitive evergreen moss-like plant with spores in club-shaped strobiles