Proc. Roy. Hort. Soc. London3: 318. 1863
Habitat: Mixed coniferous forests
Abies magnifica often exists in extensive high elevation stands in the Sierra Nevada; its close relative A. procera occurs in small mountaintop populations relatively isolated from one another. As expected for isolated populations, A. procera produces large interpopulation variation in morphology (J.Maze and W.H. Parker 1983) and chemistry (E.Zavarin et al. 1978). Where the two species meet in southern Oregon and northern California, many populations are intermediate; these have been called A. magnifica var. shastensis Lemmon. The status of such intermediates is unsettled. They may be accepted as hybrids between A. magnifica and A. procera (Liu T. S. 1971) or, alternatively, the paleontological record suggests that the two species may have originated from the intermediates (E.Zavarin et al. 1978). Individuals from this region should be assigned to A. magnifica, A. procera, or A. magnifica × procera (E.L. Parker 1963), depending on the morphologic criteria selected to differentiate the species, though clearly these individuals are genetically quite different from those near the type localities of the two species.
An extensive study of this variation, as proposed by E.Zavarin et al. (1978), is warranted. Such a study should consider data from the type localities as a basis of comparison. Moreover, to evaluate this situation critically, one should first determine if any genetic exchange occurs between Abies lasiocarpa and A. procera that may complicate an evaluation.