Abies fraseri vs silver fir

Abies fraseri and silver fir both are nouns.

Word	Noun	Adjective	Verb	Adverb
Abies fraseri	Yes	No	No	No
silver fir	Yes	No	No	No

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

Abies fraseri: small fast-growing but short-lived fir of southern Alleghenies similar to balsam fir but with very short leaves
silver fir: any of various true firs having leaves white or silvery white beneath

Abies fraseri (noun)	silver fir (noun)
small fast-growing but short-lived fir of southern Alleghenies similar to balsam fir but with very short leaves	any of various true firs having leaves white or silvery white beneath