What This project sets out to investigate the origin and age of the Greenlandic flora in relation to the island's past glacial history. While ice-sheet models suggest the presence of several ice-free "refugia" in Greenland during the Last Glacial Maximum (LGM; ~24-16 kya), at present, there is no strong evidence that Arctic biota may have survived the LGM in Greenland. Applying novel population genomic and molecular dating techniques this study will test two contrasting hypotheses: 1) floral LGM survival in Greenland, or 2) recent post-glacial floral colonisation from other Arctic regions. The outcomes will provide important new information for ice-sheet modelers and the wider climate change community, by helping to predict floral responses to past and future climate changes in the Arctic. Why Although ice-sheet models suggest the presence of several Greenlandic LGM refugia, little is known whether biota may have survived the LGM here. This project therefore aims to shed light on the Greenlandic origins of several floral species put forward as possible survivors; either because of their current occurrence in suggested refugia, their presence in harsh habitats (e.g. nunataks, polar deserts) or their extremely rare and isolated occurrence in Greenland. Finding out whether life has endured the LGM in Greenland will significantly increase our understanding of Arctic biogeography, improve our ability to model past as well as future climate scenarios in the North Atlantic and Arctic regions, and provide insights into the survival abilities of organisms through extreme conditions. How I will assess the Greenlandic origin and age of several relevant target species, making use of the vast historic collections of the Greenlandic Herbarium at the National History Museum of Denmark and other herbaria worldwide. Although the use of old and degraded herbarium specimens in genetic work has long been challenging, I will aim to use state-of-the-art genomic "target-capture" approaches to make use of these historical samples. By identifying informative variable genomic loci from several (high-quality) fresh samples, I will build a probe to "capture" these same variable genomic regions from many (low-quality) herbarium samples. The resulting data will be analysed using population genomic approaches, combined with biogeographic and molecular dating methods. SSR The outcomes will help predicting the consequences of future Arctic climate change, provide important supporting information to the ice-sheet modelling community, and aid conservation efforts and policy makers working to protect Arctic biodiversity.