Emma Lucy Braun (April 19, 1889 – March 5, 1971) was a prominent botanist, ecologist, and expert on the forests of the eastern United States who was a professor of the University of Cincinnati.

In high school, Braun herself began collecting plants for study, the beginning of a huge personal herbarium that she assembled over her lifetime, composed of 11,891 specimens.

Her collection became a part of the herbarium at the Smithsonian National Museum of Natural History in Washington D.C.[4] Braun studied botany and geology at the University of Cincinnati.

In addition to research nearby in Adams County, Ohio, and more widely in the east, Braun made 13 trips to the western United States.

Braun took numerous color photographs of the flora she encountered in her fieldwork, and displayed them as slides to illustrate her very popular lectures, both to university classes and the general public.

[8] She died in her home at age 81 of congestive heart failure, and is buried in Cincinnati with her parents and sister in Spring Grove Cemetery.

[9] Building from the understanding that the southern Appalachian mountains were a refugium for communities of forest plants during intervals of glaciation, Braun proposed two migrations of prairie flora from the western grasslands during warming periods: a pre-Illinoian movement and a post-Wisconsinan one.

[11] On the whole, Lucy Braun is considered one of the most original thinkers in North American plant ecology from the first half of the twentieth century.

[5] In 1966, Braun received the Eloise Payne Luquer Medal for special achievement in botany from the Garden Club of America.