Red fir

Related

Red fir is very closely related to Abies procera (noble fir), which replaces it further north in the Cascade Range. They are best distinguished by the leaves; noble fir leaves have a groove along the midrib on the upper side, while red fir does not show this. Red fir also tends to have the leaves less closely packed, with the shoot bark visible between the leaves, whereas the shoot is largely hidden in noble fir. Shasta red fir hybridizes with noble fir, with which it is both chemically and microscopically similar; some botanists treat the former as a natural hybrid between red and noble fir.