Humboldt’s papers contain numerous unpublished manuscripts and correspondences (including those with <ref xmlns="http://www.tei-c.org/ns/1.0" target="https://edition-humboldt.de/briefe/index.xql?person=H0006403&l=en">Karl Ludwig Willdenow</ref> and <ref xmlns="http://www.tei-c.org/ns/1.0" target="https://edition-humboldt.de/briefe/index.xql?person=H0001517&l=en">Carl Sigismund Kunth</ref>) on plant geography, which were published in 2016–2018 in the <hi xmlns="http://www.tei-c.org/ns/1.0" rendition="#i">edition humboldt digital</hi>. A curated selection was published in 2020 as Volume 1 of <ref xmlns="http://www.tei-c.org/ns/1.0" target="https://www.springer.com/series/16348">Series III "Forschungen im Umfeld der Reise"</ref> of the <ref xmlns="http://www.tei-c.org/ns/1.0" target="https://www.springer.com/series/16345"><hi rendition="#i">edition humboldt print</hi></ref> entitled <ref xmlns="http://www.tei-c.org/ns/1.0" target="https://www.springer.com/gp/book/9783476049643"><hi rendition="#i">Geographie der Pflanzen: Unveröffentlichte Schriften aus dem Nachlass</hi></ref>.