Abies is the genus that contains all true fir species.

Firs tend to have poor decay resistance. Some species are mixed with other softwoods and used in construction under the label “SPF,” which stands for spruce, pine, fir. 

Abies species

Abies alba
Abies amabilis
Abies balsamea
Abies bracteata
Abies cephalonica
Abies concolor
Abies fraseri
Abies grandis
Abies lasiocarpa
Abies magnifica
Abies procera
Abies religiosa