Taxonomy of intraspecific taxa of Abies lasiocarpa: Leaf essential oils and DNA of Abies lasiocarpa var. bifolia and var. arizonica

Detailed analyses of the leaf essential oils of Abies lasiocarpa var. lasiocarpa (Olympic Peninsula, WA), A. l. var. bifolia (MT, UT) and A. l. var. arizonica (AZ) is presented to update the analyses of Hunt and von Rudloff (1979). The coastal alpine fir (A. l. var. lasiocarpa) is very strongly differentiated from all the Rocky Mtn. populations in having only a trace of camphene, no limonene, a large amount (53.3%) of β-phellandrene, no borneol, a large amount of piperitone (9.2%), methyl citronellate (0.4%), only a trace of bornyl acetate (0.1%), and a small amount of thymol (2.3%). The oil of A. l. var. bifolia has considerable amounts of (cpd., MT%, UT%): α-pinene (8.5, 3.4%), camphene (8.4, 15.0%), β-pinene (10.1, 16.5%), β-phellandrene (6.0, 4.1%), bornyl acetate (21.2, 24.9%) and thymol (3.5, 12.5%). The oil of A. l. var. arizonica has considerable amounts of α-pinene (9.2%), camphene (15.2%), β-pinene (24.0%), β-phellandrene (5.1%) and bornyl acetate (34.4%). The oil is differentiated by having no δ-3carene, (E)-β-ocimene, trans-p-menth-2-en-1-ol, methyl citronellate, thymol, geranyl acetate or (E)-α-bisabolol. DNA sequencing of nrDNA, trnS-trnG, trnL-trnF, petN-psbM, and psbM-trnD yielded 5655 bp of data. NJ tree and SNPs analyses revealed the corkbark fir (A. l. var. arizonica) of the southern Rocky Mtns to be the most distinct of the taxa. Based on the oil and DNA data, there is support for the