Analysis of the Oils of Western North American Junipers by Gas‐liquid Chromatography

Oil samples from six species of Juniperus include 37 detected components, of which most are quantitatively highly variable. Nine chromatographic patterns were identified, including one for each of two subspecies of J. occidentalis and, surprisingly, two different patterns in both J. californica and J. monosperma. The chemical evidence supports earlier taxonomic conclusions based on morphology and natural history that J. occidentalis subsp. occidentalis and J. occidentalis subsp. australis are indeed subspecies, that the former is intermediate between the latter and J. osteosperma , and that J. californica and J. osteosperma are closely related but distinct species. It is concluded that the techniques of gas chromatography have considerable potential as a taxonomic tool.