The Lomatium grayi complex (Apiaceae) of the western United States: a taxonomic revision based on morphometric, essential oil composition, and larva-host coevolution studies

  • Jason Andrew Alexander University of California, Berkeley, University and Jepson Herbaria
  • Wayne Whaley Utah Valley University, Department of Biology
  • Natalie Blain Utah Valley University, Department of Biology


The Lomatium grayi complex is morphologically diverse across it range. The type species of this complex, Lomatium grayi s.s., has been found to not be a host of the larvae of Papilio indra, while the other three morphotypes are larval-hosts. A fifteen character, morphometric analysis was conducted on 390 herbarium specimens from throughout the range of this species. PCA, MANOVA, CDA, and Tukey tests revealed that the majority of the characters in this dataset were significantly different between four regional morphotypes. As a result of the morphometric analysis, the morphotypes are herein proposed as four species. Two new species are proposed for populations of L. grayi in the Pacific Northwest. Lomatium papilioniferum is proposed for plants in California, western Idaho, northern Nevada, Oregon, and Washington. Lomatium klickitatense is proposed for populations of robust plants from western Klickitat County, Washington, and northern Hood River County, Oregon. Lomatium grayi var. depauperatum is elevated to a species. This leaves no infraspecific taxa within L. grayi s.s. A presence/absence phenetic analysis of combined essential oil data was inconclusive regarding the composition of L. grayi s.s., which was found to be more similar to Lomatium klickitatense and Lomatium depauperatum than other species of Lomatium. Taxonomic treatments for each of the four species in this complex are provided. A key to these species and the multiple species that have been commonly mistaken for L. grayi is also included.


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How to Cite
Alexander, J. A., Whaley, W., & Blain, N. (2018). The Lomatium grayi complex (Apiaceae) of the western United States: a taxonomic revision based on morphometric, essential oil composition, and larva-host coevolution studies. Journal of the Botanical Research Institute of Texas, 12(2), 387-444.