Vascular Plants of Northern Death Valley National Park (Death Valley, Last Chance Range, and Eureka Valley), Inyo County, California

The northern portion of Death Valley National Park closely (but not entirely) corresponds to the northernmost portion of the Mojave Desert in California. From 2014 through 2019 we surveyed the vascular plants in the Eureka Valley, northern Last Chance Range, and northern Death Valley. This study area covers 1735 sq km and ranges in elevation from 810 to 2577 m; it contains the tallest sand dunes in California, a calcium-rich mountain range, and alkaline seeps. These features provide specialized habitats for narrowly and regionally endemic plants. Fossil data from packrat middens suggest that the local climate has become warmer and drier during the Holocene and the assemblage of plants currently observed has only been in place for a few thousand years. During six years of fieldwork, we documented 542 specimens of minimum-rank taxa, including 51 special concern taxa and 25 non-natives. We were unable to relocate 45 taxa known from historic collections. Fifty-one collections were the first for the study area; these include 24 range extensions. Observations from our collections are combined with those from historic collections and other collectors in an annotated checklist