California Native Plant Society

Rare Plant Program

History of the CNPS Rare Plant Program and Inventory 

(from CNPS Inventory, 6th Edition, 2001)

Rare plant studies have been a focus of the California Native Plant Society since its beginning. In 1968, G. Ledyard Stebbins, who was then President of the Society, started a card file of California plants with a distribution of less than one hundred miles. These cards were sent to botanists to solicit comments. Under the direction of Roman Gankin, Chairman of the newly formed Rare Plant Committee, these comments were evaluated and many more plants were suggested for consideration. Several in-house lists, composed of over 800 plants, were circulated during the next three years. The first widely distributed CNPS list appeared in 1971. It contained 520 plants.

At the same time, W. Robert Powell became Director of the Rare Plant Project. Early in 1973 a major effort was mounted to update and expand our information. Again in-house lists were circulated. The high-point of these activities occurred in July 1974, when a number of professional and amateur botanists from throughout the state met for a mapping session at the University of California at Davis. This provided an excellent opportunity for the participants to share their knowledge, often incomplete, of California's rare and endangered plants. It should be emphasized that from the beginning, CNPS rare plant investigations have been based upon the first-hand knowledge and field experience of a statewide network of botanists who have been generous in their cooperation. We continue to map locations in detail, confirm the existence of plants in the field, and record changes in population size as we refine our dataset.

In December 1974, the Society published the first edition of its Inventory of Rare and Endangered Vascular Plants of California, under the editorship of W. Robert Powell. In its Main List were 704 plants of primary concern. A second list was formed of 554 plants considered rare but not presently endangered. In addition, 135 plants were listed as being of limited distribution but not rare. This brought the total of plants included in the first edition to 1,393 species, subspecies, and varieties. At the time of its publication, the CNPS Inventory was the most detailed compilation of rare plant data for any state in the nation. It quickly became the most widely used reference on the subject in California, and the prime source of information for botanists, private consultants, conservationists, and the staffs of city, county, state, and federal agencies.

Many of these same individuals, in return, provided new information, refinements, and corrections. CNPS responded by issuing supplementary lists of additions and deletions. With each passing year, it became more obvious that a second edition of the Inventory was needed. In November 1979, the U.S. Fish and Wildlife Service and CNPS co-sponsored a second review conference, once again on the Davis campus. About fifty specialists gave freely of their time and energy to amend and correct provisional lists that CNPS had developed for a proposed second edition.

The second edition appeared in 1980, with James P. Smith, Jr., R. Jane Cole, and John O. Sawyer, Jr. as editors. There were several format changes. This time 1,383 plants were arrayed in four lists, the first one entitled "Presumed Extinct in California." This was done in an effort to bring special attention to 44 plants that were then known from historic collections only. It became a challenge to see if any of them could be rediscovered (and several of them were). The plants on these four lists were adopted by the California Department of Fish and Game as constituting its Special Plants List. A supplement to the second edition was published in 1981, and another in 1982.

The appearance of the new edition was followed quickly by two other major events in the Society's Rare Plant Program - the hiring of Richard York as a full-time botanist and the signing of a Memorandum-of-Understanding with the California Department of Fish and Game's Natural Diversity Database (CNDDB). The rare plant data that already existed in our files, together with the accelerated pace of acquiring new information, had outstripped the capacity of our group of volunteers to maintain current manual files and to respond to inquiries in a timely fashion. A full-time employee had become a necessity. Our agreement with CNDDB led to establishing the CNPS botanist's office and files within the facilities of the California Department of Fish and Game, the state agency charged with inventorying rare, threatened, endangered, and sensitive plants and with preparing the documentation needed for state listing of these plants. For a more complete history of the Society's Rare Plant Program and the role of the CNPS Botanist, see Berg and Skinner (1990), Powell (1975, 1978), Powell et al. (1981), Smith (1987, 1990), Tibor (1999), and York et al. (1982).

Planning for the third edition of the Inventory began in late 1982. Meetings were held the following year to discuss possible format changes and to solicit information on incompletely known plants. In July 1983, through the generosity of many CNPS members, the Rare Plant Program was able to purchase a computer. The work of entering all of our rare plant data into the computer began that summer and was completed in a relatively short time. In February 1984, we once again held a statewide meeting of amateur and professional botanists at the University of California at Davis. The third edition was published later that same year.

Work on the fourth edition began in March 1987, with the conversion of our computerized data to dBase III+ files. Advances in database management software improved our ability to organize and analyze the data and allowed electronic coordination with CNDDB. To update our information, a list of proposed status changes was circulated to more than 200 data contributors for review. We also requested that any new status or distribution information be brought to our attention at that time. Meetings were held in Sacramento and Berkeley in December 1987, to discuss final status recommendations and to receive outstanding field survey data. These solicitations resulted in an avalanche of documentation.

In assimilating this information, we systematically reevaluated the rarity and endangerment ratings for more than 700 of our highest priority plants. County and topographic quad data were compared with CNDDB computer files. Habitat occurrence data were assembled, categorized, and computerized for more than 1,300 plants. This information was reviewed by botanists at the CNDDB, Department of Fish and Game Endangered Plant Project, and The Nature Conservancy. The fourth edition was published in September 1988.

Work on the fifth edition commenced in earnest in Spring 1991, when we conducted primary research for two new fields of information, life form and blooming time. In June 1991 we circulated a request for new information to the data contributors, now numbering about 370. Later that year we began the laborious process of library and herbarium research on the more than 300 plants which are newly added to this addition, and on the more than 35 plants shifted from List 4 to one of the higher priority lists. Also in late 1991, with extensive help from CNDDB, we commenced a detailed comparison with the taxonomic concepts and other information contained in The Jepson Manual, the monumental new work on California's flora. This task extended into June 1992, and entailed hundreds of name, status, and distribution changes. In April of 1992, we circulated preliminary review lists of status changes and new plants to the contributors. We received well over 100 responses with thousands of suggested changes and improvements. In August 1992, all proposed changes to date were reviewed in Sacramento by the Rare Plant Scientific Advisory Committee (RPSAC) and several knowledgeable guests, and by July 1993 the first complete draft of the data in this volume appeared for review. RPSAC members, CNDDB staff, and a number of other selected experts reviewed the data one final time in Fall 1993, and hundreds of last minute changes and corrections were made at that time. The fifth edition was published in February 1994.

Efforts on the sixth edition began in mid-1994. Research on elevational range for all taxa was completed by late 1994. We queried several floristic databases to identify possible rare plants for addition, and other comparisons were performed to find possible deletions, status changes, and the like. These queries resulted in the need for a large amount of library and herbarium research. In November 1995, preliminary review lists of Inventory changes were circulated to about 400 botanical experts around the state. From 1996 through 1998, research and review continued on over 600 new additions, 400 status changes, and other modifications proposed for the sixth edition. In mid-1998 and early 1999, RPSAC was reorganized with the assistance of Barbara Ertter, focusing on a regional approach. Eleven RPSAC regional meetings were held around the state during much of 1999. These meetings represented an effort to bring the proposed changes for the sixth edition directly to the regional botanical experts for review and formation of consensus. Over 300 individuals were invited to these meetings, and many of them attended or presented opinions and data in absentia. At the conclusion of these meetings, the consensus opinions and new data were then processed, with assistance from CNDDB. A large amount of follow-up work, typically on taxonomic issues, was completed through early 2000. The recommendations of RPSAC also generated the need for more herbarium and literature work, completed during the first half of 2000.

Literature Cited

Berg, K., and M. Skinner. 1990. The CNPS botanist is a reflection of the Society. Fremontia 18(4):13-15.

Powell, W.R., ed. 1974. Inventory of Rare and Endangered Vascular Plants of California. Special Publication No. 1 (first edition). California Native Plant Society. Berkeley, CA. iii + 56 pp.

Powell, W.R. 1975. The CNPS Rare Plant Project. Fremontia 2(4):14-19.

Powell, W.R. 1978. The CNPS Inventory - a progress report. Fremontia 5(4):28-29.

Powell, W.R., T. Duncan, and A.Q. Howard. 1981. The California Native Plant Society Rare Plant Project. Pages 193-198 in: L.E. Morse and M.S. Henifin, eds. Rare plant conservation: geographical data organization. New York Botanical Garden. Bronx, NY

Skinner, M.W. and B.M. Pavlik, eds. 1994. Inventory of Rare and Endangered Vascular Plants of California. Special Publication No. 1 (fifth edition). California Native Plant Society. Sacramento, CA. vi + 338 pp.

Smith, J.P., Jr., ed. 1981. First Supplement, Inventory of Rare and Endangered Vascular Plants of California. Special Publication No. 1 (second edition). California Native Plant Society. Berkeley, CA. 28 pp.

Smith, J. P., Jr. 1987. California: leader in endangered plant protection. Fremontia 15(1):3-7.

Smith, J. P., Jr. 1990. A history of the rare plant program and Inventory. Fremontia 18(4):9-12.

Smith, J.P., Jr., and K. Berg, eds. 1988. Inventory of Rare and Endangered Vascular Plants of California. Special Publication No. 1 (fourth edition). California Native Plant Society. Sacramento, CA. xviii + 168 pp.

Smith, J.P., Jr., and R. York, eds. 1982. Second Supplement, Inventory of Rare and Endangered Vascular Plants of California. Special Publication No. 1 (second edition). California Native Plant Society. Berkeley, CA. 28 pp.

Smith, J.P., Jr., and R. York, eds. 1984. Inventory of Rare and Endangered Vascular Plants of California. Special Publication No. 1 (third edition). California Native Plant Society. Berkeley, CA. xviii + 174 pp.

Smith, J.P., Jr., R.J. Cole, and J.O. Sawyer, Jr., eds. 1980. Inventory of Rare and Endangered Vascular Plants of California. Special Publication No. 1 (second edition). California Native Plant Society. Berkeley, CA. vii + 115 pp.

Tibor, D. 1999. The CNPS rare plant program. Fremontia 27(2):4-6.

York, R., J.P. Smith, Jr., and S. Cochrane. 1982. New developments in the rare plant program. Fremontia 9(4):11-13.

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