The book that botanists, government planners, gardeners and weekend hikers depend on to learn more about California's plant life is bigger and better than ever, thanks in part to students and faculty at SF State.

The 2nd edition of the Jepson Manual of Vascular Plants of California, weighing in at an impressive nine pounds, includes work by SF State biology professors Robert Patterson, Tom Parker, nine former SF State graduate students and one graduate student.

They provided detailed descriptions of some of the state's native and weedy plants, puzzled out the relationships between plant families and in some cases even tramped into California's less-traveled corners to uncover new or long-forgotten species.

"Our botany program is small, but very high caliber," Patterson said. The program's emphasis on plant systematics -- the study of the relationships between plant species -- made its graduate students a natural choice to work on the Jepson Manual.

"Some of our students did their master's thesis projects on specific groups of plants, and you really take ownership of a group when you take on that kind of project," said Patterson, who co-wrote several entries and was an editor for the entire manual.

While a graduate student at SF State, Charles Bell began work on the Jepson entries for the Adoxaceae family of viburnums and elderberries and the Caprifoliaceae family of honeysuckles and their relatives. "Then during my Ph.D. work I became sort of the expert on these groups," said Bell, now a biology professor at the University of New Orleans.

Others, like current graduate student Scott Simono, took on the entries for such plants as the buttercup family and the buckwheat family when no other experts were available. "Working on the manual introduced me to a lot of California botanists," said Simono. "I also learned a lot about scientific publications, plant taxonomy and herbariums that -- as herbariums disappear -- fewer and fewer students have access to, at least at an undergraduate level."

Patterson said the manual's new edition contains a much more accurate reflection of plant relationships, based in part on a wealth of genetic information that has become available since the first edition. For instance, the lily family "used to be a very inclusive group, but in this second edition the Liliaceae plants have been distributed around 14 different families," he said.

The new designations may cause some confusion to manual users at first. But Patterson said accurate plant identification and new information on plants' distribution around the state are essential to guide responsible land use and conservation.

"There are also a number of additional weedy species included compared to the first edition, along with more native plants that have been recognized," said Patterson. "The new guide can help us follow the new weeds that are coming into the state every day, and becoming more aggressive every day."

"The classification and identification of plants in some cases are relying on 100-year old ideas," said former SF State graduate student Stephen McCabe, who worked on the family of "live-forevers" plants for the new edition. "Having people who can go into the field -- checking to see if these plants exist anymore and how many species are there -- is critical to being able to protect species and habitat."

McCabe, now the director of education at the UC Santa Cruz Arboretum, said his time at SF State "prepared him perfectly" for his contribution to the new volume. "Unfortunately, there are fewer and fewer places in the California and the United States where you can be trained for the kind of work that goes into the Jepson Manual."

"There's a new batch of students working on the flora of North America who are conscientious and field-savvy and diligent, and they are a tremendous resource," said Patterson.

The Jepson Manual, named after pioneering California botanist Willis Linn Jepson, is available from the University of California Press, and is also connected with a variety of electronic resources at the Jepson Online Interchange.