Lomatium Species of the Intermountain Western United States: A Chemotaxonomic Investigation Based on Essential Oil Compositions

Lomatium is a genus of 98 species, widely distributed in western North America. This work presents a chemometric analysis of the essential oils of seven species of Lomatium (L. anomalum, L. dissectum var. dissectum, L. multifidum, L. nudicaule, L. packardiae, L. papilioniferum, and L. triternatum var. triternatum) from the intermountain western United States (Oregon and Idaho). The essential oils were obtained by hydrodistillation and analyzed by gas chromatographic methods. Lomatium packardiae essential oil can be characterized as limonene-rich, L. anomalum is a species rich in sabinene and &alpha:-pinene, and L. multifidum essential oils were rich in myrcene, while L. dissectum var. dissectum essential oils were dominated by octyl acetate and decyl acetate, L. papilioniferum essential oils from western Idaho had high p-cymene and 2-methyl-5-(1,2,2-trimethylcyclopentyl)phenol concentrations, while those from Oregon had relatively high &beta:-phellandrene and sedanenolide levels. The essential oils of L. triternatum var. triternatum were too variable to confidently assign a chemical type. The major components in the L. nudicaule essential oils were &beta:-phellandrene (16.0&ndash:45.7%), (Z)-ligustilide (5.6&ndash:47.1%), (E)-&beta:-ocimene (3.3&ndash:9.9%), and &delta:-3-carene (0.2&ndash:12.6%). The enantiomeric distributions of &alpha:-pinene, camphene, sabinene, &beta:-pinene, limonene, and linalool were also utilized to discriminate between the Lomatium taxa. There are not enough consistent data to properly characterize L. triternatum var. triternatum or the Oregon L. papilioniferum essential oils. Additional research is needed to confidently describe the chemotype(s) of these species.