Herbarium: When William Trelease took over as the first director of the Missouri Botanical Garden following the 1889 death of Henry Shaw, he built the institution's herbarium upon the foundation of two previous collections brought together by Engelmann. The first of these was the Bernhardi Herbarium purchased by Engelmann on Shaw's behalf in 1857, and the second was Engelmann's personal collection which passed to the garden some time after his death in 1884. Sorting and mounting these into the institution's herbarium took time as there were 57,500 specimens in the Bernhardi Herbarium and more than 98,000 in Engelmann's.¹ To these Trelease and other researchers added their own specimens over time to create the large MBG herbarium of today which holds nearly seven million specimens.

Trelease and the garden staff embossed each mounted specimen with a seal identifying them as part of the Engelmann Herbarium. As of the end of 2013, there are now 11,651 digitized specimens on Tropicos.org bearing the embossed seal. You can view these from the left hand menu or by selecting the embossing image above.

References: The Peter H. Raven Library at the Missouri Botanical Garden has been a founding partner in the launching of the Biodiversity Heritage Library, which was originally built upon the architecture of MBG's own Botanicus.org. As Botanicus was created for holding the taxonomic literature related to specimens on Tropicos.org, various published materials written by Engelmann and his collaborators found their way online in support of the digitization of the Engelmann Herbarium. In support of the specimens collected on the expanded American frontier, the Digitizing Engelmann's Legacy project digitized more than 100 volumes of published works resulting from the various expeditions represented. These volumes are partially representative of Engelmann's published writings and of the work of his collaborators. The complete list can be browsed from the associated BHL collection. A complete hyperlinked list of Engelmann's publications is currently available on Wikipedia in the article George Engelmann bibliography.

Papers: Throughout George Engelmann's life he maintained an active exchange of letters with correspondents in Europe and America in English, French, and German. Among Engelmann's personal papers at the Missouri Botanical Garden archive, there are more than 5,000 letters addressed to Engelmann by almost 600 different correspondents. In 2013, the Engelmann Correspondence Project digitized these letters and uploaded them to the Biodiversity Heritage Library. An updated finding aid to Engelmann's papers is available on the collection's landing page and they can also be browsed by their title, author, and year. The letters at the Missouri Botanical Garden are incoming letters that Engelmann kept over the course of his career. The outgoing letters that Engelmann wrote are scattered in different archives around the world, and they have largely not yet been scanned.