A New Variety of Lomatium ravenii (Apiaceae) from the Northern Great Basin and Adjacent Owyhee Region

Variability in the group of Lomatium species comprising L. nevadense, L. ravenii, and L. foeniculaceum has led to conflicting classification schemes. While some taxonomists have treated L. ravenii as a distinct species made up of all the populations from California, Nevada, Idaho, and Oregon, others considered L. ravenii to be nothing more than a morphological extreme of L. nevadense. We examined morphological and phylogenetic data from across the range of L. ravenii, concluding that variation in the species warrants varietal distinction. Non-metric multidimensional scaling analysis of 29 populations shows two distinct groups—one from the vicinity of Ravendale, California, and one from the rest of the range in California, Nevada, Oregon, and Idaho. Phylogenetic analysis of the ITS, rps16 intron, and cpDNA rpl32-trnLUAG genes from seven populations supports these two groups. We refer to the geographically widespread population as Lomatium ravenii var. paiutense and recommend reassessment of the conservation status of the more narrowly endemic Ravendale populations.