BOOKS : A Mum by Any Other Name Will Be in ‘Flora’

Plant names and descriptions enter the computer age with the beginning volumes of “Flora of North America,” an ambitious and ongoing project to catalogue information on the plants of North America. But the age-old complaint--”Why did those darn botanists change the name of my favorite plant?”--seems likely to be around a while.

Even so, “Flora” should become a well-thumbed reference work, not only for botanists but also average gardeners and amateur naturalists.

It’s not for the average home library, however. The first two of the projected 14-volume series cost $75 each and run close to 400 pages.

The information will also be available in computer-database form, a first. Another advantage of such a database is that it can be continually updated.

Missouri Botanical Garden in St. Louis led the effort to produce the books, and the first one is dedicated to Peter H. Raven, director of the garden.

“This is not only a culmination of an effort that goes back several centuries, it’s also a new beginning,” Raven said.

Hundreds of U.S. and Canadian botanists are participating in describing North America’s estimated 20,000 species of plants. The work follows the monumental system for classification of flowering plants developed by Arthur Cronquist of the New York Botanical Garden, who died in 1992.

The work so far has taken a decade and is expected to take another 12 years. The budget now is $1 million a year, supported by the National Science Foundation and philanthropic groups. The goal is to provide a single, dependable source of information.

The “Flora” project reflects a growing movement to refer to plants by their botanical names, on the theory that this is the only way to be sure of what you are buying. Common names have become more and more meaningless as people move to new areas.

For example, what do cornflower, bachelor’s button and centaurea have in common? Quite probably they will be the same flower, only with different regional names. It really gets hilarious with Dusty Miller, a name given to at least a half dozen different plants with gray foliage.

But just as the idea of using botanical names makes headway, along come a name change that many see as ridiculous. How many dendranthema do you have in your landscape? After several hundred years, that’s the new botanical name for chrysanthemums.

Yoder Brothers, the country’s major producer, says as far as it can tell, most folks still are calling them mums.

Botanists have long contended that they do not change names on a whim, but only when they discover that a name--many of them dating from the early 1700s--breaks the rules or when new research changes the plant relationships.

“Flora of North America treatments are based on critical evaluation of the literature, examination of specimens, and field and laboratory experience,” notes Volume 1.

Volume 1 is a series of essays on the natural history, classification and similar aspects of plants. During a 22-page commentary, Cronquist says that “nothing can be more certain than that future studies will lead to changes in the system” of classifying plants.

Volume 2 is an in-depth look at ferns and gymnosperms, including evergreens and pines. The description of the maidenhair tree ( Ginkgo biloba ), which is widely planted in this country, is particularly interesting: “The genus is known from fossils that date back nearly 200 million years and are nearly identical to present-day trees.”

The text notes that in the ginkgo’s native China it “is either extinct in the wild or drastically restricted in range” and says planting of the female ginkgo usually is discouraged because of their obnoxious odor.