Abies venusta vs true fir

Abies venusta and true fir both are nouns.

Word	Noun	Adjective	Verb	Adverb
Abies venusta	Yes	No	No	No
true fir	Yes	No	No	No

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

Abies venusta: 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 Abies venusta include fir, fir tree.

Abies venusta (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