Bizarre blooms of Baja: with a variety of habitats and weather conditions, this pristine peninsula harbors a range of unique plants.

• Author: Cohn, Jeffrey P.

Mark Dimmitt was puzzled. The creeping devil cacti that he and his colleagues sought on Mexico's Baja California Peninsula were not where memories from previous trips told him to look. Not only could he not fred the mysterious cacti, but the Pacific Ocean was not where his maps and the car's odometer said it should be. After some head scratching, though, Dimmitt, director of natural history at the Arizona-Sonora Desert Museum in Tucson, plowed ahead over a few more tall sand dunes. Soon he found himself surrounded by hundreds of the alien-looking creeping devils, all pointing in different directions.

There are perhaps few plants in the world stranger than the creeping devil cactus. Known on Baja as chirinola or casa de ratas (rat house), the creeping devil reaches about five to ten feet in length. It has long, very sharp spines, large white flowers that bloom at night and scarlet-colored fruit. The cactus is found in only place--on sandy softs near the Pacific coast of the Magdalena Plains in southern Baja.

But none of those characteristics are what make the creeping devil strange. Rather, it is the way the cactus grows. Unlike most plants that grow upright, the creeping devil lies flat on the ground, its front end tipped up. Roots descend wherever the cactus touches the soil. Even stranger, it continues growing from its front end while the back dies and disintegrates. Thus, anyone who revisits a patch of creeping devils after several years' absence might think the plants had moved or crept from one place to another.

The creeping devil is just one of many Baja plants that look weird, have strange-sounding names, or unusual characteristics. These include the boojum and elephant trees, a bursage with fruits more like a cactus, and such real cacti as the sour pitahaya and cardon. Moreover, botanists are still finding strange new species on Baja and strange new things about plants that seemed already well known.

"Baja plants are weird, not only in their looks but in many other aspects," says Jon Rebman, curator of botany at the San Diego

Natural History Museum. Dimmitt agrees. He calls the creeping devil "bizarre," adding: "In Baja, where there are so many strangelooking plants, such thoughts are mundane."

Not only does Baja have a lot of unusual plants, but a surprising diversity, too. With more than four thousand taxa or related groups of plants, more than most U.S. states, the peninsula is the most diverse part of the Sonoran Desert, says Rebman. Thirty percent of all Baja plants grow only there. Of the 130 taxa of cacti growing on Baja, 70 percent are found nowhere else.

Scientists are not quite sure why Baja has such a variety and so many unusual plants, but they cite several factors. One is the location, sheer size, and shape of the place. Located in northwestern Mexico, it has often been called "Baja incognito," "the forgotten peninsula," and "almost an island." It is separated from the Mexican mainland by the Gulf of California (also called the Sea of Cortes). The long, thin peninsula stretches more than eight hundred miles from the U.S.-Mexican border at Tijuana to the tip at Cabo San Lucas, but is only 50 to 150 miles wide. Baja is nearly twice as long as Florida, the longest peninsula in the United States. Only the Malay Peninsula in Asia is longer.

Because of its length, Baja encompasses a tremendous variety of habitats. They range from Pacific coastal chaparral in the northwest to thick thorn scrub, palm trees, and a tropical dry forest in the subtropical southern cape. In between are pine, aspen, and oak-covered mountains, with one, the Sierra San Pedro Martir, rising more than ten thousand feet in elevation. Bays lower Pacific and gulf coasts feature mangrove wetlands and nutrient-rich blue lagoons that attract numerous whales and other marine mammals. Rocky islands dot the gulfs offshore regions.

But the largest and most biologically interesting areas of Baja are the deserts that dominate...