bristlecone fir vs true fir

bristlecone fir and true fir both are nouns.

Word	Noun	Adjective	Verb	Adverb
bristlecone fir	Yes	No	No	No
true fir	Yes	No	No	No

As nouns, true fir is a hypernym of bristlecone fir; that is, true fir is a word with a broader meaning than bristlecone fir:

bristlecone fir: a pyramidal fir of southwestern California having spiny pointed leaves and cone scales with long spines
true fir: any of various evergreen trees of the genus Abies; chiefly of upland areas

Other hypernyms of bristlecone fir include fir, fir tree.

bristlecone fir (noun)	true fir (noun)
a pyramidal fir of southwestern California having spiny pointed leaves and cone scales with long spines	any of various evergreen trees of the genus Abies; chiefly of upland areas