Benjamin Smith Barton

Today is the birthday of the American botanist, naturalist, and physician Benjamin Smith Barton.
Barton worked as a professor of natural history and botany at the University of Pennsylvania, where he authored the very first textbook on American botany. In 1803, Barton tutored Meriwether Lewis to get him ready for the Lewis and Clark Expedition. Lewis had little knowledge of natural history and plants. Barton's expertise made it possible for him to be quite effective on the expedition.
Barton was supposed to create a book describing all of the plants that were found on the expedition. But, for some reason, he never began writing. The job ultimately fell to Barton's assistant, Frederick Pursh, who ended up having a falling out with Barton. Pursh took copies of the specimens and went to England, where he found a patron and published his Flora of North America — much to the chagrin of Benjamin Smith Barton and other botanists.
And, there's a fun story that came out last year, in February, about this time. And, it was about a little yellow butterfly that was found pressed between the pages of a Barton manuscript - his Flora Virginica - from 1812. It turns out that this little yellow creature was found by a library fellow named E. Bennett Jones at the American Philosophical Society as he was looking through the book. Butterfly experts felt the placement was purposeful since the butterfly was found in between the pages listed "plants beloved by pollinators - such as Monarda." 
After the discovery, the Barton butterfly was carefully removed and preserved in a suspended container. In a touching result, the manuscript will forever bear a butterfly-shaped stain - marking the spot where the little butterfly was pressed between its pages for over 200 years before it was discovered.