Originally published in 1963, the late Julian Steyermark's Flora of Missouri has been the principal reference on plant life in the state. It also has been used widely in surrounding regions and has served as a model for floristic manuals in the United States. Although out of print and in serious need of revision, it has continued to be an essential tool for land managers, conservationists, ecologists, taxonomists, foresters, wildlife biologists, and other students of Missouri's diverse flora. In 1987, in recognition of the need for an up-to-date reference on the state's flora, the Missouri Department of Conservation and the Missouri Botanical Garden agreed to jointly sponsor the production of a thoroughly revised manual. The present volume is the first of three that are intended to fulfill this promise.

Steyermark's Flora of Missouri is an account of Missouri's vascular flora, including the pteridophytes, gymnosperms, and flowering plants growing spontaneously in the state. Volume One contains treatments of 801 species of ferns, fern allies, conifers, and monocots. Users of the previous edition will note similarities in format, with keys to families, genera, species and infraspecific taxa, full-page plates of line drawings and county dot maps for each species. The revised edition, however, features all-new illustrations and simplified maps generated from a computerized database of specimens. The keys have been streamlined, and morphological descriptions have been added to the text. Taxonomic changes and additions are documented in a lengthy bibliography.

Volume One also includes a series of introductory chapters that summarize the state's climate, geology, vegetation and flora, as well as changes since publication of the first edition. A history of the floristic botany in Missouri commemorates the numerous men and women who have contributed to knowledge of the state's flora. A glossary and a "how to" section complete the background materials in the book.

Steyermark's Flora of Missouri is intended to be a reference tool for professionals in biology and related fields, and also for the large group of dedicated amateur botanists and naturalists who have created the unique environment in which conservation, natural history, and outdoor activities thrive and are supported in the state.