The "Endless Forms" Thematic Collections Network (TCN), composed of 17 collaborating U.S. herbaria from 11 states, will digitize approximately two million specimens belonging to some of the most interesting plant species on Earth. Iconic species such as the Giant Saguaro Cactus, the Venus Fly Trap, and the leafless Ghost Orchid of southern Florida are just a few of the hundreds of thousands of plants that have evolved astounding adaptations allowing them to grow in extreme terrestrial environments, including deserts, tropical rain forests, and nutrient poor bogs. Many of these plants can also be challenging to study in nature and face elevated conservation concerns in the face of rapid environmental change. By digitizing herbarium specimens of these groups, researchers will gain a better understanding of these adaptations and their evolution, and can design conservation and management strategies. The public's interest in these unusual plants affords an opportunity to engage k-12 students and teachers in discussions about biodiversity and preservation, plant adaptations, and mutualistic relationships. This project will also train undergraduate and graduate students in the areas of museum studies. Finally, the availability of two million digitized records for these charismatic plant groups will help protect them and enhance their enjoyment by hobbyists, citizen scientists, and other non-academic enthusiasts<br/> <br/>This "Endless Forms" project is the first TCN initiative to digitize the very significant holdings of non-North American specimens housed within North American herbaria. This project will provide access to digitized records of 15 plant families associated with adaptations to extreme terrestrial environments that can be used to test evolutionary and ecological hypotheses. This network will, for example, provide data that can be used to explore trait development and evolution, species delimitation, and geographic distribution modelling and that can inform national and regional floristic projects. This project will help provide critically needed information to overcome obstacles related to studying plant families which are very large, have cryptic diagnostic features, or occur in geographically challenging areas. This TCN will also help overcome an acute problem of access to specimens of CITES-listed taxa (species threatened with extinction) by easing data access and by holding a Plant Collecting Ethics Workshop that will bring together an array of stakeholders to make recommendations on best practices for handling sensitive data for rare species. The project will fill taxonomic and geographic gaps in U.S. institutional specimen digitization, will bring new institutions into the national digitization effort and will invest in the development of tools to stream-line the digitization process. This award is made as part of the National Resource for Digitization of Biological Collections through the Advancing Digitization of Biological Collections program and all data resulting from this award will be available through the national resource (iDigBio.org).<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.