ground pine vs club-moss

ground pine and club-moss both are nouns.

Word	Noun	Adjective	Verb	Adverb
ground pine	Yes	No	No	No
club-moss	Yes	No	No	No

As nouns, club-moss is a hypernym of ground pine; that is, club-moss is a word with a broader meaning than ground pine:

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

Other hypernyms of ground pine include club moss, lycopod.

ground pine (noun)	club-moss (noun)
any of several club mosses having long creeping stems and erect branches	primitive evergreen moss-like plant with spores in club-shaped strobiles
low-growing annual with yellow flowers dotted red; faintly aromatic of pine resin; Europe, British Isles and North Africa