"The Jepson Desert Manual, Vascular Plants of Southeastern California," published this spring by the University of California Press and replete with color photos, illustrates the spare beauty that draws people year after year into the heat of Death Valley or the Mojave Desert for spectacular flower shows.

"People find the contrast between lush displays and stark landscape beautiful and intriguing," said Bruce G. Baldwin, associate professor of integrative biology at the University of California, Berkeley, and one of the manual's editors. "The resurrection of plant life is amazing - after years and years of lying dormant in the seed bank it can burst forth into incredible displays."

The manual's 128 color photographs, many by Baldwin, prove the case. Baldwin's photo of a carpet of desert sunflowers in Death Valley during the wet 1998 spring graces the back cover.

"The Jepson Desert Manual presents examples of the great variety and beauty of California's deserts," he said.

These deserts include the Mojave east of Los Angeles, the Sonoran Desert in extreme southeast California, and the southern Great Basin environment, including the White Mountains, east of the Sierra. According to Baldwin, southern California's desert parks couldn't keep the manual in stock this spring, despite the poor flowering season.

The desert manual was designed with the amateur as well as the professional in mind, he said. He and the many editors worked hard to keep the size of the soft cover book down so that it could easily be carried into the field. For that reason, it excludes Mediterranean-climate plants that border and often creep into the western edges of California's desert areas, and leaves out plants of the arid areas of northeastern California.

The plant descriptions are taken from "The Jepson Manual, Higher Plants of California" (UC Press), updated since its publication in 1993 and augmented by more detail on flowering times and distribution, several new plant keys and some 300 new illustrations. The Jepson manuals are a project of the Jepson Herbarium at UC Berkeley, a repository of California plants named after the late botanist Willis Linn Jepson, an avid desert collector. The herbarium compiled and edited the 1993 state-wide manual that replaced Jepson's original 1925 "Manual of the Flowering Plants of California," the standard reference for the state's vascular plants.

Baldwin, curator of the Jepson Herbarium, noted that new scientific data, much of it based on DNA comparisons, have led to extensive reclassification and discovery of Californian plants within the past decade. The Jepson Herbarium keeps a running account of taxonomic changes and new additions to the California flora on its Web site, the Jepson Online Interchange.

The bulk of the color photos were supplied by John Game, a yeast researcher at Lawrence Berkeley National Laboratory who serves as an unpaid research associate at the Jepson Herbarium and photographs wildflowers in his spare time.

"I adore going to the desert and photographing flowers," Game said. "What I like about the desert is that the flowers tend to be very showy and very unusual-looking. You really feel you are in a different world."

The California deserts appeared in their modern form only within the past 10-12,000 years, Baldwin said, overlapping the appearance of humans in the area. Over this time, as the climate became drier, conifers and other plants of cool, wetter environments became restricted to high-elevation refugia and once-isolated pockets of creosote bush and burro-weed expanded to become the dominant vegetation over most of the lowlands. The desert mountains and the Death Valley region are modern hot-spots of endemism in the California deserts, with numerous species found nowhere else in the world.

Luckily, Baldwin said, few non-native plants have managed to invade the desert areas, with only a handful - red brome, tumbleweed, and some mustards, for example - marring their undisturbed beauty.

"In the desert you see the natural community the way it was before there were humans around, so you feel you are really out in the planet as the planet should be," Game said.