Plant diversity darkspots for global collection priorities

Summary More than 15% of all vascular plant species may remain scientifically undescribed, and many of the >340,000 described species have no or few geographic records documenting their distribution. Identifying and understanding taxonomic and geographic knowledge shortfalls is key to prioritising future collection and conservation efforts. Using extensive data for 343,523 vascular plant species and time-to-event analyses, we conducted multiple tests related to plant taxonomic and geographic data shortfalls, and identified 32 global diversity darkspots (regions predicted to lack most information about their species diversity and distribution). We defined priority regions for future collection according to several socio-economic and environmental scenarios. Most plant diversity darkspots are found within biodiversity hotspots, except New Guinea. We identify New Guinea, the Philippines, Borneo, Myanmar, India, Turkey, Colombia, Ecuador, and Peru, as global collection priorities under all environmental and socio-economic conditions considered. Our study provides a framework to accelerate plant species documentation for the implementation of conservation actions. As digitisation of the world’s herbaria progresses, collection and conservation priorities may soon be identifiable at finer scales.