Most prospective homebuyers would look at a deeply discounted teardown on a 1.6-acre spread in the oh-so-exclusive West Los Angeles neighborhood of Bel Air and think, \”McMansion!\”

Not UCLA plant environmental biologist Park S. Nobel, who found himself in that precise situation in 1993. In the sun-drenched site with a modest \’50s home, Nobel remembers being attracted by a lonely stand of cacti on a slope thick with weeds — and immediately realized he had found an ideal showcase for his revolutionary ideas about the environmental benefits of cacti and succulents.

\”I drove up the street, and I told my daughter, \’If those plants are on the property, I\’m buying it!\’\” recalls the distinguished professor emeritus in the Department of Ecology and Evolutionary Biology. In fact, the Life Sciences veteran made a full-price offer without having set foot on the grounds, much less inside the house.

Now 18 years later, Nobel\’s home about a mile north of campus is a one-of-a-kind demonstration garden. From floppy-eared prickly pear and soaring towers of organ-pipe-like cereuses to spiky century plants, examples of the most familiar cacti and succulents jostle for attention with phalanxes of truly rare specimens.

This is a place to glimpse nearly two dozen different species of ground-hugging, flower-studded mammillaria, 14 species of octopus-like agaves and as many species of opuntia, the Latin name for prickly pear. In all, the property brims with close to 5,000 plants that require little water, thanks to Nobel\’s specialty as a researcher — crassulacean acid metabolism, or CAM.

\”Welcome to Casa de CAM!\” he announces during a recent exclusive tour for UCLA Magazine. He greets his visitor wearing a shirt with a label that reads \”cactus.\” Through the shirt\’s placket peeks a cream T-shirt emblazoned with a multicolored agave. The septuagenarian\’s face — leathery from years of fieldwork in sunny locations — radiates enthusiasm.

As the world\’s leading authority on the environmental biology of agaves and cacti, the author of more than 300 scientific articles and the author/editor of 16 scholarly books on these staples of the desert Southwest, Nobel uses his garden as a kind of beachhead for a quiet revolution. Governors may come and go. Warnings of droughts may be issued and rescinded. And statewide water allotments may wax and wane. But at Casa de CAM, the wet stuff is never an issue. Every year, the landscape doesn\’t just limp along, but actually thrives on nothing more than what falls from the sky.

Look what can grow on 15 inches of rainfall!

But illustrating the type of landscape that survives without irrigation is relevant beyond Southern California. Nobel contends that global climate change will dramatically increase the territory where these heat-tolerant plants can thrive by curtailing one of their only known foes: freezing temperatures. Indeed, high heat tolerance, low water needs and a prodigious ability to sequester carbon dioxide ideally suit agaves and cacti for the challenges of global warming, he argues.

In addition to their ability to withstand a hotter, drier future, the plants offer many more benefits, Nobel says. They are a tried-and-true source of cattle feed, food for Type II diabetics, plant-based hormones for pharmaceuticals, fiber for rope, and carbohydrates for biofuel — all with less wear and tear on the environment than conventional sources. He even believes the plants have a future in the global carbon-credit market, as massive carbon sinks capable of making a real dent in the world\’s carbon footprint.

\”We\’ve just begun to tap their potential,\” says Nobel, who makes his case in a self-published book called Desert Wisdom: Agaves and Cacti, C02, Water, Climate Change.

Nobel was fresh from a divorce when he found his future home. Purchased by a developer who went bankrupt in 1989, the property was owned by a bank and the house had been occupied by squatters. \”It was a drug haven for the neighborhood,\” he remembers. \”Drug users came in here and cooked in every room in the house. It was in total shambles.\”

Realtors, in fact, refused to step foot on the property. They insisted that the house was in such bad shape it should be torn down, but Nobel wouldn\’t listen. He carted out rats, mice, lizards, insects and spiders. He replaced floors, which in some places were worn through to the concrete slab. He replaced kitchen cabinets that had been beaten up. He neutralized walls that had been painted green, blue and pink.

Neat as a pin today, the house has been returned to its mid-century modern glory, what Nobel\’s companion Cathy Goodman M.S.W. \’70, D.S.W. \’80 calls \”an indoor-outdoor house\” with generous views of the garden. They share their home with their 4 1/2-year-old border collie, Bee Cee.

But making the house habitable was nothing compared to whipping the grounds into shape. Starting from the bottom, Nobel worked alongside crews to clear the land of dead ice plant and fire-prone grasses and sumac. He then laced the property that climbs 221 feet up a steep, shale-strewn slope with one-sixth of a mile\’s worth of paths that wind visitors through his magnificent plant collection.

The first specimens came from the home he shared for 15 years with the mother of his two daughters, now grown. Nobel had accumulated most of the plants with a special import license during research expeditions. From fieldwork in Chile came his Opuntia ficus-indica, a fast-growing prickly pear whose pads are especially tasty when young. (Desert Wisdom includes a recipe for these \”nopalitos.\”) From the Mexican state of Zacatecas came the rounder, thicker-padded Opuntia robusta, which deer mysteriously bypass on their way to nibble at other prickly pear varieties. And from Coahuila — another Mexican state — came the small, compact Agave lechuguilla, whose thin, green spikes are traditionally harvested to make baskets, twine and upholstery stuffing.

Over the years, neighbors have contributed cuttings to Nobel\’s garden. That\’s how he came by a soft carpet of Lampranthus deltoids, a dainty, gray-blue succulent distinguished by lavender stems. Another subset of plants hails from local homeowners who got in over their heads. An example is the three-story-tall spray of cereus that erupts high up on Nobel\’s slope.

\”Those were given to me by a lady in Valley Village,\” he says. \”When I got it 15 years ago, it was this tall,\” he adds, motioning to his hip.

Whatever the source, the variety — at least 50 species of cactus alone — is dazzling: Furry columns of old man cactus wait to ensnare passersby with their abundant, fine needles. Waxy-leafed Portulacaria afra — a South African native otherwise known as elephant bush — proudly stands sentinel. Tall, elegantly branching Myrtillocactus geometrizans evoke Arizona\’s majestic saguaros. And with pin-like protrusions all over their cylindrical bodies, Austrocylindropuntia subulata looks like an acupuncture treatment gone awry.

Other plants were gifts from fellow cactus lovers. Arthur C. Gibson, the director of UCLA\’s Mildred E. Mathias Botanical Garden (many of Nobel\’s treasures are discards from the Botanical Garden) and coauthor with Nobel of a 1986 cactus primer, bought him a golden barrel cactus — also known as mother-in-law\’s seat — as a birthday present 25 years ago. Now plump and imposing, the prize specimen is planted prominently near Nobel\’s back patio.

Nobel figures his property is about one-quarter the size of the Mathias garden, which is tended by four full-time employees and more than 10 volunteers. By contrast, he maintains the grounds on Verano Road by himself, devoting eight to 10 hours every week to weeding, trimming, moving plants and replacing them. Yet he insists he wouldn\’t have it any other way.

\”I\’m not an artist, but I have the feeling that I want to create something besides my writing and my research,\” Nobel says. \”This is my palette.\”