On a warm Florida afternoon, Mike Owen steps off a forest trail into dark, knee-deep water. He pockets the little yellow waterproof notebook in which he records everything he sees in the Fakahatchee Strand State Preserve and sloshes deeper into the swampy shadows. "You’re within 250 feet of 12 species of orchid," he calls over his shoulder to four hikers. "But you won’t see ’em if you don’t get in the water."

But the hikers stay on the trail, and Owen shrugs. A resident biologist at the preserve, he’s used to people who don’t want to get their feet wet. After all, the place is full of snakes—22 species of them, including pygmy rattlesnakes and cottonmouth moccasins. Then there are the alligators, manatees, Everglades mink, panthers and black bears. Not even Owen will come into the swamp at night or alone in daytime. "Too risky, too easy to get hurt," he says.

Despite the dangers, Owen, 43, is one of those happy few working precisely the job they want. "I’ll probably never leave," he says, smiling. He came to the Fakahatchee in 1993 after stints as a park ranger and a fisheries department field technician. With a volley of facts and a boyish flood of wows and goshes, he explains the swamp’s history, topography, plant and animal life to a steady stream of visitors, up from about 300 a day to 350 since the 1998 publication of Susan Orlean’s best-selling book, The Orchid Thief, which tells the true story of an obsessive collector named John Laroche and his scheme to poach the Fakahatchee’s rare orchids. The book was also the basis of the 2002 movie Adaptation, starring Nicolas Cage, Chris Cooper as Laroche and Meryl Streep as Orlean. (Of Cooper’s portrayal of Laroche, Owen says, "That’s him! So conceited, and very intelligent!")

Since the book and movie came out, thieves have made off with four more endangered orchids, and now Owen takes visitors on "indirect routes" during swamp walks to see the exquisite plants. "I have to be real careful," he says. "I could have an orchid poacher with me."

There are about 25,000 wild native orchids in the world and perhaps 100,000 hybrids, he says. "The Fakahatchee is the orchid capital of the country. It has the most species of anyplace in the United States, half tropical and half temperate."

Among them is the legendary ghost orchid—Dendrophylax lindenii. Leafless with bright white spindly petals on slender spikes, the flower seems to float in the air. It was the ghost that Laroche sought most fanatically and that provided the centerpiece of Orlean’s book, and it’s the ghost we’re seeking today.

The Fakahatchee Strand State Preserve, 80 miles west of Fort Lauderdale, is a two-foot-deep, 5-by-20-mile channel through the limestone prairie of southwest Florida that enriches the estuaries southeast of Naples. Over the centuries, organic material collected in this shallow trough, forming a rich layer of peat. "It’s like a big valley filled with sponge," Owen says.

Bald cypress trees proliferated in the nutrient-laden slough, some growing to 100 feet. During World War II, loggers harvested the rot-resistant, old-growth trees, up to six feet in diameter, to build minesweeper hulls and PT boats, and later, pickle barrels, stadium seats, shingles and coffins. The loggers’ railway roadbed, with its narrow spurs jutting fingerlike into the swamp, now forms a scenic drive and a network of dry hiking trails. Today the Fakahatchee—"river with muddy banks" in Muskogee, a Seminole language—is home to the country’s grandest stand of royal palms and its richest concentration of wild orchids and bromeliads.

The hikers’ voices fade behind us as we slosh deeper into the dim gray-green world of water and plants, brilliant shafts of sunlight piercing the landscape at sharp angles. Owen’s head darts like a wading bird’s. "What you see depends on the angle of light and openness of the canopy," he says.

The water is the color of weak tea and a cool 72 degrees even in summer. Owen stops, looking up. "Here’s a ribbon orchid on a pop-ash tree, nine feet up!" He records the sighting in his yellow notebook: orchid and tree species, height, water depth. "No blooms yet. October’s the best month for blooms."

Entering a water-filled clearing about 20 feet wide, we navigate cypress knees poking up from the water and Spanish moss hanging from the trees. "And here’s a canoe orchid!" Owen exclaims. "See the rigid keel on the leaf?"

Owen is gesturing, lecturing, ticking off points on his fingers. "It’s the water, the canopy and the peat that makes it!" he says, waving a pencil. "The topography determines wetness—the strand fills with water during the rainy season, and the peat holds the water, keeps it humid so the trees can grow and protects it from desiccation and fire. The canopy shades the understory and moderates the temperature and cuts the wind." He plunges on, talking a mile a minute, deeper into the swamp.

"Now, here’s a night-scented orchid. It blew in on a hurricane two-three-four hundred years ago, and even though there’s no pollinator here, it turns out to be self-pollinating."

Owen’s knowledge of orchids wasn’t nearly so extensive when he first arrived at the strand, and as it happens, it was John Laroche who facilitated his education. Owen had been on the job just two months when Laroche and three Seminole Indians were caught with pillowcases and plastic bags full of rare plants, just like in the movie. "He had 92 orchids of nine species and some rare bromeliads," Owen says. (Laroche was fined $500 and banned from the park for six months.) "He was very friendly right after he was caught. We didn’t know the plants like he did, so he taught us about all the orchids he had." They included the ghost.

Ghost orchids were rather common before a 1977 frost decimated them and before too many people learned to brave the dark, wet swamp. Poachers like Laroche reduced the ghost’s numbers steeply. "It’s a touchdown if you find one," Owen says.

As if on cue, we suddenly find ourselves staring at a ghost. Owen points at it with his pencil. "This one has no spikes, so it hasn’t bloomed yet." At this stage, the plant is an unprepossessing little network of gray-green roots, like a mass of rubber bands stuck to the tree. "It blooms in June, July or August. They’re pollinated at night by the sphinx moth, with a six-inch wingspan and a six-and-a-quarter-inch tongue!"

We move on, but in a few moments, Owen is glancing around uncertainly, and I think of Chris Cooper as Laroche in Adaptation, reassuring an up-to-her-hips-in-swamp-water Streep, "We’re not lost." I stumble into a deep hole and barely catch my balance. Shadows are lengthening. I can hear the whir of night insects. It’s almost dusk when we emerge from the Fakahatchee. The hikers are gone.

Owen excitedly counts up the orchids we’ve seen. Eleven? Twelve? As we head back to the truck, he starts telling me about ferns.