Chris du Plessis leans over the edge of his open-air truck, eyes riveted on the dirt road like an animal tracker.
"There!" he yells, and slams on the brakes, jolting the vehicle to a halt.
In the back, two camera-laden South African couples and a German tourist with a video recorder strain to follow his gaze. Mr. Du Plessis jumps out of the truck (a 1978 farm vehicle refitted with safari-style seating) and dashes to the side of the road.
"Look at this," Du Plessis announces triumphantly. "Grielum humifusum!"
Between thick, weathered fingers, he pinches a tiny yellow flower. Its gentle, pale petals waver in the wind as he gazes proudly. He points out the color gradations – pale yellow to white and, in the center, deeper yellow – and talks about its trick for pollination. (Dark yellow attracts infrared light-seeing insects.)
The tourists murmur appreciatively, and point their cameras.
This is the fifth flower tour that Du Plessis has led in three days on his farm near Clanwilliam,2-1/2-hours north of Cape Town. And he's booked solid for 10 days. It's the norm, he says, during western South Africa's spring flower season, from early August to mid-September when the scrubby mountainsides and valleys here erupt into a rainbow of petals.
The 350-mile stretch from Cape Town up the Cedarberg mountains and to the Kalahari Desert, is one of the richest floral kingdoms on earth, with more flora species than in the whole Amazon jungle, say experts. Within a swath of that kingdom are the short-blooming wildflowers – in some regions making carpets of orange and white and pink, in others forming patches alongside the proteas and wild shrubs called fynbos. Reds, blues, and magentas are everywhere.
Just around Clanwilliam, says Cecilly Muller, the chair of the Clanwilliam Wildflower Society, there are more than 2,000 species – more than in any other one district in the world, she adds. The bounty includes more than 400 types of geraniums (the ones sold in the US originally came from here) and more than 100 types of gladioli.
Locals have long paid homage to flower season – they all know their flowers by common names like "violin" and "young man's button" and "snow." But recognition of tourist potential didn't start until the 1960s when Clanwilliam started holding flower dances. A few years later the Clanwilliam Wildflower Society was formed and started fund-raising flower shows. City folk from Cape Town regularly drove up for August weekends – think New Yorkers leaf peeping.
But in recent years, the number of far-flung tourists – from elsewhere in South Africa and abroad – has skyrocketed. This year's Clanwilliam Wildflower show drew double the attendance it had had in 2006 (7,000 came this year). Local innkeepers and tour guides say they've seen a growing business related to the flowers.
At Clanwilliam's information center, the visitors' book is filled with international entries: "Very beautiful place," writes Dwight from Hawaii. "Beautiful, peaceful place and stunning flowers," offers the Wilson family from Oman.
"We're finding more and more visitors coming this time of year," says Kate Bergh, the director of Cedarberg African Travel. She's seen busloads of Japanese tourists and backpackers from the US. But the average flower tourists, she says, are retired couples, often from England. "We get mother-daughter pairs, too," she says with a laugh. "The husband won't go, so the daughter gets roped into it."
There are tricks to successful flower touring. First of all, it's best to visit during a good flower year, Ms. Muller says. That's a year when the first rains come in with the fall in early April, and then about every second week through the South African fall and winter.
"It doesn't need to be a lot, but a little bit at a time," she says. "By the middle of July we know whether we are going to have a good year."
A regional flower hot line allows visitors to check bloom status. But even in good years, flowers can be fickle – and a tad lazy. They stay closed at night, and only open when the sun is high and hot. (The word "daisy," du Plessis points out, came from "day's eye," and refers to flowers that open during the day.) They don't open on days that are too cold, too cloudy, or too windy. And then, when they do unfurl, they always face the sun. "If you drive down the road one way, you won't see anything; if you go the other way you will," says Ms. Bergh.
Bergh, who runs four-day flower tours, says it's impossible to promise her clients a particular itinerary – they have to make last minute decisions based on where the flowers are best. The company sends out feelers to check the landscape, she says, and some of her guides get inside information from farmers, many of whom open up their property to flower tourists.
Visitors not on an organized tour can go to local information centers for of the day's best flower route. That's what Ronel and Leon Eksteen were doing at the Clanwilliam information center earlier this month. The couple, from across the country in northeast South Africa, had come for the day's flower map. "It's just so beautiful!" Mrs. Eksteen gushes. "We'd seen brochures, but now we are experiencing it for ourselves."
Ms. Muller, the Wildflower Society chair, says that tourists tend to fit into one of two categories: the type who want see what people call "carpets of flowers" – seas of pinks and oranges found in the northern Namaqualand region – and those interested in botany. She says that the longer tourists stay in the region, the less they get excited about carpets and the more they admire the rare flowers seen only by getting out and walking.
She falls squarely in the botany category herself. "Ooh, you have to take a picture! These are my favorite. Heliophila coronopifolia," she says to a visitor on a drive outside Clanwilliam, pointing to purple-blue flowers wavering on taller stalks.
Her mother started the Clanwilliam Wildflower Society in the early 1970s, and today Muller lives on the flower-filled farm once run by her parents. As she walks through a field pointing out different varieties, she's looking for a green, almost orchid-looking bloom and says, "I can't let you leave until you see this particular flower.
"See, you can't actually come for one day," she adds."You at least need three."