The genus Lomatium is the largest of 18 genera of Apiaceae from primarily Western North America that form a large clade of over 200 species. This website is the result of an NSF funded project to create a phylogenetic hypothesis and a new classification for this previously poorly understood group. This electronic monograph contains descriptions, synonymy, protologues, distribution maps, specimen records, and photographs for all taxa in this group. Phylogenetic trees and GenBank records of DNA accessions used in our study are also included.

The 18 genera covered in this treatment are: Aletes, Cymopterus, Eurytaenia, Harbouria, Lomatium, Musineon, Neoparrya, Oreonana, Oreoxis, Podistera, Polytaenia, Pseudocymopterus, Shoshonea, Taenidia, Tauschia, Thaspium, Vesper, and Zizia.