Douglas Fir Needle Oil
There are seven species of Pseudotsuga found in their natural environment in eastern Asia and western North America (Airy Shaw, 1966). The taxonomic origin of Douglas fir is Pseudotsuga menziesii (Mirb.) Franco. This tree is highly valued in the timber industry of western North America because of its rapid growth habit.
According to Krüssman (1985), P. menziesii exists as a coastal form var. menziesii and a mountain form var. glauca (Beissn.) Franco. Numerous forms and cultivars of Douglas fir are known although no studies have been performed on the relationship between form or cultivar and essential oil composition.