First thanks goes to every author and collector who is cited herein as they did the actual work upon which this assemblage was based. Similarly to the assorted databases and herbarium records online. Those databases are included in the references listed.
I want to also thank a host of helpful friends, book vendors and information services for helping me obtain reference materials.
However, this project would have been vastly more difficult if not for the activities of a growing number of organizations that exist with the apparent intentions of digitizing everything possible and/or making knowledge more readily available. In alphabetical order: Archive.org, Biblioteca digital del Real Jardín Botanico CSIC (Madrid), Biodiversity Heritage Project, MOBOT’s Botanicus, the Canadian Forest Service, Citationsy, Galica at the Muséum national d’histoire naturelle, Google, Hathitrust, and Alexandra Elbakyan’s Sci-Hub.