Christmas holly vs holly

Christmas holly and holly both are nouns.

Word	Noun	Adjective	Verb	Adverb
Christmas holly	Yes	No	No	No
holly	Yes	No	No	No

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

Christmas holly: an evergreen tree (Ilex opaca)
holly: any tree or shrub of the genus Ilex having red berries and shiny evergreen leaves with prickly edges

Other hypernyms of Christmas holly include poisonous plant.

Christmas holly (noun)	holly (noun)
an evergreen tree (Ilex opaca)	any tree or shrub of the genus Ilex having red berries and shiny evergreen leaves with prickly edges