Skip Navigation and banner
This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.
University of Wyoming

Flora of the Rocky Mountains Project


The only two regional floras are Coulter and Nelson's New Manual of Botany of the Central Rocky Mountains (Vascular Plants) published in 1909 (covering Colorado, Wyoming, most of Montana, the Black Hills ofSouth Dakota, southern Idaho, the eastern half of Utah, the northern half of New Mexico, and adjacent Arizona) and Rydberg's Flora of the Rocky Mountains and Adjacent Plains: Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and Neighboring Parts of Nebraska, South Dakota, North Dakota, and British Columbia published in 1917. The former was a new book, written by Nelson to replace John M. Coulter's earlier work (1885), but the latter was given senior authorship (Williams 1984). It was a relatively conservative treatment for the time and thus quite popular. Rydberg's Flora covered a much lingerer area, but extensive splitting at the species level greatly decreased its utility. Obviously, both are now obsolete except for historical purposes. Weber's Rocky Mountain Flora (1967 and revisions) is a misnomer representing little more than a revision of his useful Handbook of the Plants of the Colorado Front Range (1953 and revisions); it is of limited use beyond the Colorado Rockies.

The current project (Hartman 1990a, 1990b) was initiated with a symposium entitled The Flora of the Rocky Mountain Region (RMR) held at the Southwestern and Rocky Mountain Division of the American Association for the Advancement of Science Meeting in Colorado Springs, May of 1990. Speakers were Jane M. Beiswenger, Paleofloristics (Quaternary) of the RMR; Stanley A. Morain, Origin and evolution of the Rocky Mountain flora; William A. Weber, Phytogeographical affinities between the Rocky Mountains and Asia; William H. Moir, Vegetation zones and plant communities of the RMR; Theodore M. Barkley, The success of the Flora of the Great Plains Project; Stanley L. Welsh, The success of the Utah Flora Project; and R. L. Hartman, Floristic inventories andthe Flora of the Rocky Mountain Project. Many of these authors will be contributing chapters to the Introduction for the Flora. Other contributors include Brainerd Mears, Jr., Physiography and geomorphology of the RMR; Roger L. Williams, Botanical exploration of the RMR; S. A. Morain, Plant geography and floristic divisions of the RMR; and R. L. Hartman, Endemism in the RMR.

The Flora of the Rocky Mountains: Vascular Plants of the Rocky Mountains and Adjacent Plains and Basins, North America (FRM) will consist of five or six volumes with a format similar to that of the Intermountain Flora (Cronquist et al. 1972 and subsequent ones) although certain modifications will be adopted from Flora of North America (FNA Editoral Committee 1990). A guide for contributors of taxonomic treatments to the Flora is nearing completion.

The goal is to coordinate the publication of the Flora of the Rocky Mountains with that of the Flora of North America, although the plant families occurring in two volumes of FNA will be covered in one volume of the Flora. The Flora volume will be published approximately two years after the corresponding ones for North America. Consequently, the Flora will be written along the lines of FNA. That is, in the pejorative, it will be a "flora by committee." More correctly, it will be a flora by experts, at least wherever possible. Although this method can lead to considerable hardship for the editor, more often than not, it leads to a greater approximation of reality with regard to the taxa recognized and thus a more enduring work. As a member of the Editorial Committee of the Flora of North America project, I am in a good position to evaluate the work of a specialist prior to inviting the individual to participate in the Flora. Unfortunately, for many authors, the Flora is queued behind The Vascular Plants of Arizona project and likely other floras.

Volume one, like the floras of North America and Intermountain Region, will consist of the introductory chapters (mentioned above) and taxonomic treatments of the ferns, fern allies, and gymnosperms. Illustrations from the Vascular Plants of the Pacific Northwest (Hitchcock, et al. 1955, 1959, 1961, 1964, and 1969) and the Intermountain Flora will be used with permission where appropriate. For the first volume, about 25% of the taxa will need illustrations.

The area covered by the Flora (Fig. 4) includes the Canadian Rockies south of Pine Pass (Hart and Continental ranges and the Purcell and Selkirk mountains; Alberta and British Columbia), all of the Montana, Wyoming, and Colorado, and portions of Washington (Stevens and Pend Oreille counties), Idaho (Bannock, Portneuf, Chesterfield, Bear River, Aspen, Caribou, and Snake River ranges and intervening areas of the southeast portion and that north of the Snake River Plains, excluding the Snake River Canyon and adjacent land below ca. 4,000 ft), Utah (La Sal, Uinta, Wasatch, and Wellsville mountains), South Dakota (Black Hills) and New Mexico (an inverted, roughly triangular area covering the north-central 20% of the state, south to the break in the mountains between Santa Fe and Albuquerque).

Justification for covering all of Montana, Wyoming, and Colorado in the Flora includes: 1) it will be useful to many more people, 2) many of the species in the plains to the east also occur in foothills adjacent to the Rockies and in intervening basins, 3) the western plains were not covered well in the Flora of the Great Plains (Great Plains Flora Association 1986) as most of the specimen studied were from herbaria in the central tier of the region, 4) and finally, there are several examples of major floras which overlap in coverage such as the Manual of Vascular Plants of Northeastern United States and Adjacent Canada (Gleason and Cronquist 1991) with the Flora of the Great Plains (Great Plains Flora Association 1986) and the Vascular Flora of the Southeastern United States (Cronquist 1980). Such overlaps in coverage are valuable in providing different taxonomic and regional perspectives on a flora.

Following the publication of the Flora, an atlas of the region is planned using specimen databases established at herbaria throughout the region and the latest technologies in GIS and computer cartography. This will be of tremendous use in phytogeographic, ecological, and systematic studies.

The Flora of the Rocky Mountains project represents a collective effort by the systematics community in the region and throughout North America. If the proposed Flora is to represent accurately the geographical range, ecological amplitude, morphological variability, and other aspects of the vascular plants of the region, additional floristic projects will be necessary. A coordinated effort by a number of herbaria and museums is needed. Although much of the fieldwork may not be completed in time to be reflected in all of the volumes, it is hoped that the knowledge gained from these efforts will be included in a supplement to or a revision of the Flora. Such information certainly can be incorporated into specimen and taxon databases.

In conclusion, the goal is to have the Flora published within the next 12 to 15 years with help from systematists throughout North America. To this end, a Rocky Mountain Flora Association is being formed to coordinate efforts for completing of fieldwork, for the data basing of specimens, and for the preparation of the Flora.