How much progress has North America made toward the Global Strategy for Plant Conservation (GSPC) Target 8 of at least 75% of threatened plant species in accessible ex situ collections by 2020? To answer this, the North American Collections Assessment was carried out in 2010. More than 200 botanical and conservation institutions in the United States, Canada, and Mexico contributed taxa lists to the Botanic Gardens Conservation International's (BGCI) online PlantSearch database for this assessment. By cross-referencing collection information with globally threatened species lists from the International Union for Conservation of Nature and Natural Resources (IUCN), NatureServe, and Mexico's Red List, we found that approximately 35% of North America's nearly 5000 most threatened taxa are currently in ex situ collections. This marks considerable progress toward the GSPC Target 8, but there is clearly much more to do. Future priorities include collaboratively and strategically increasing threatened species representation in collections and assessing genetic diversity among collections by comparing accession-level data.