The Flora of Missouri project is an ongoing effort to update and compile information on the state’s flora. It began in 1987 as a joint effort of the Missouri Botanical Garden and the Missouri Department of Conservation. One of its main goals is a three-volume revision of former Missouri Botanical Garden curator Julian A. Steyermark’s Flora of Missouri, first published in 1963. Missouri’s ever changing plant diversity, the shifting distributions of its plant species, and the many new records of plants in the state have necessitated an expansion of Steyermark’s original publication into three volumes. Volume 1 of the new encyclopedia was published in 1999; Volume 2 was published in June 2006. The third and final volume was published in August of 2013.

Steyermark’s Flora of Missouri, Second Edition: Volume 1 contains lengthy introductory chapters on climate, geology, vegetation and botanical history, as well as treatments of the pteridophytes, conifers, and monocots. Volume 2 contains the first half of the dicot treatments, including members of the parsley, carnation, honeysuckle, milkweed, morning glory, mustard and sunflower families. Each volume has more than 1,000 pages and features dot maps, descriptions, identification keys, flowering times and habitat information, along with new, original black-and-white illustrations of nearly all of the species. 

In 2009, the project embarked on an ambitious effort funded by the Institute for Museum and Library Services (IMLS) to make information on Missouri plants more widely accessible on the World Wide Web. Text from the printed Volumes 1 and 2 has been reformatted and digitized to allow full access on the web. Additionally, high-resolution scans of herbarium specimens of Missouri plants are available, and many photographs of plant species in the field are being uploaded. New tools have been developed to produce maps of the county-level distributions of the plants as well as other views of specimen occurrences. All of this material is available through the online version of the Garden’s plant database, Tropicos®, at http://www.tropicos.org/Project/MO.

Field work by Missouri botanists from colleges and universities, state and federal agencies, and private organizations, along with specimens donated by amateur enthusiasts, continue to increase the Garden’s holdings of the state’s flora by about 5,000 specimens per year. The information from many of the specimen labels is being added to the Tropicos® database and thus updating the distribution maps available online for each species.

The Flora of Missouri project is directed by Garden Curator, Dr. George Yatskievych. Rex Hill is the project’s database manager. Ann Larson, Nancy Walker and Jack Harris volunteer their services to the project.

Published volumes of Steyermark’s Flora of Missouri, Second Edition are available from the Missouri Botanical Garden Press, www.mbgpress.org or 1 (877) 271-1930, and the Garden Gate Shop, (314) 577‑5137.