One is the loneliest number: The plants of One Known Occurrence in the USA and Canada

Our new geologic era requires modern approaches for preventing extinction events. Previous work on plant extinctions in the United States and Canada identified that 64% were single-site endemics (Knapp et al. 2021). This agrees with a recent global analysis of plant extinctions that showed taxa from one area/or with extremely limited geographic ranges are the most common trait shared for all extinct plants (Humphreys et al. 2020). Current methodologies used by the International Union for the Conservation of Nature (IUCN) and NatureServe do not explicitly identify or prioritize taxa of One Known Occurrence for conservation action. Currently, ca. 1250 taxa are given the highest conservation status rank, G1 – Critically Imperiled with Extinction. Given the lack of funding available for plant conservation, it is obvious additional prioritizations are needed to meaningly prevent extinctions. This project, funded by the US Botanical Garden, has identified what plants are single-site endemics (SSE) or have declined to One Known Occurrence (OKO) in the USA and Canada. In situ and ex situ conservation methods should be employed for all SSE and OKO plants if such actions haven’t already occurred. During this talk, we will present the results of this analysis, identify which are most in need of in situ and ex situ conservation actions, and discuss where these are found. A separate analysis was conducted to identify where single-site endemics cooccur.