Lycopodium alpinum vs club-moss

Lycopodium alpinum and club-moss both are nouns.

Word	Noun	Adjective	Verb	Adverb
Lycopodium alpinum	Yes	No	No	No
club-moss	Yes	No	No	No

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

Lycopodium alpinum: a variety of club moss which occurs throughout northern latitudes in the Northern Hemisphere (Lycopodium alpinum)
club-moss: primitive evergreen moss-like plant with spores in club-shaped strobiles

Other hypernyms of Lycopodium alpinum include club moss, lycopod.

Lycopodium alpinum (noun)	club-moss (noun)
a variety of club moss which occurs throughout northern latitudes in the Northern Hemisphere (Lycopodium alpinum)	primitive evergreen moss-like plant with spores in club-shaped strobiles