Maria Watkins, left, has her picture taken at the Smithsonian Folklife Festival with Colombian coffee icon Juan Valdez, depicted by coffee farmer Carlos Castaneda. (Astrid Riecken/For The Washington Post)

The man in the white hat with the striped poncho folded neatly over his left shoulder steps iconically among coffee trees growing this week near the Washington Monument on the Mall. He probes the green, marble-size fruit with thick, nimble fingers. The fruit will turn cherry red when it ripens, he says, as though the fate of nations and human happiness depended on it. Which they do.

Wait, haven’t we seen you before, humble and handsome stranger? The hat, the poncho, the leather pouch, the blue-striped shirt, the khakis, the woven sandals — the mustache!

All that’s missing is dramatic guitar strumming and the smoky, Spanish-inflected commercial voice-over intoning, “One-hundred-percent Colombian coffee. It’s the richest coffee in the world — hand-picked by Juan Valdez.”

Instead, a different voice breaks in, 100 percent American, braying with excitement.

“Juan Valdez! My hero Juan Valdez! I’ve been looking for you for 20 years! I found Juan Valdez! Juan Valdez!”

Lou Quander, from Alexandria, a retired crew chief for Delta Airlines wearing a Colombia baseball cap, races to the coffee grove ahead of his Colombian-born wife, social worker Magda Leon. For the 20-plus years of their marriage, they’ve been visiting her family in Colombia, drinking Colombian coffee, and she’s been telling him about the mythical Juan Valdez, who, in the Colombian psyche, is no mere advertising mascot. He’s almost a national treasure.

The man in the white hat understands little of Quander’s English, but the American’s enthusiasm is universal.

“My 18-year-old daughter is vacationing in Fiji,” Quander says. “When she gets back, I’m going to tell her, ‘Your father shook the hand of Juan Valdez!’ ”

Juan Valdez — as personified by one Carlos Castaneda, 44, a real Colombian cafetero, or coffee grower — arrived in Washington in late June as part of Colombia’s display in the Smithsonian Folklife Festival, which continues Thursday through July 11. (Castaneda’s last day at the festival was Monday, though coffee-growing demonstrations continue.)

No legal export sums up Colombia’s world identity like coffee, nor is as important to its economy, social fabric and internal sense of self-worth. And nothing symbolizes Colombian coffee like Juan Valdez.

Americans are accustomed to reserving a measure of contempt for advertising icons, even as we eagerly consume the products. Juan Valdez — and Colombians’ affection for him — is different. He’s got a little bit of the Marlboro Man and the Jolly Green Giant in him. But also the stuff of legend and national character, like a Paul Bunyan or a Johnny Appleseed.

Since 1959, when the image was conceived on Madison Avenue, only three men have been entrusted with portraying Juan Valdez. The first was a Cuban American actor, Jose Duval. The second, Carlos Sanchez, was a Colombian painter and actor who had dabbled in coffee as a young man.

Castaneda took over the job in 2006 after an elaborate, top-secret search that he stumbled into by chance. The grandson and son of cafeteros, Castaneda started working in the coffee fields at about age 6. Now married with three children, he owns a finca of about 7.5 acres and 15,000 coffee trees on a hilly slope outside the town of Andes, about 80 miles from Medellin. Until he became Juan Valdez, he never had been to Bogota, nor on an airplane.

One afternoon, he stopped in a cafe in the town plaza for — what else? — a cup of coffee. Slick types were casting farmers for some sort of documentary. Did he want to participate? Sure. Someone snapped a picture and sent it to Bogota.

Castaneda was among about 400 cafeteros from 80 towns that agents of the National Federation of Coffee Growers of Colombia — keepers of the Juan Valdez national brand and logo — selected to compete for the role. Over several weeks, Castaneda and the others were put through tests. The marketers needed someone who knew coffee, looked attractive yet real, had a stable family and no vices, and who could mix well with diplomats, business people, reporters and the public all over the world.

Psychologists asked Castaneda what he would do if he weren’t selected Juan Valdez.

“I said, ‘That’s fine. I’ll go back to my finca, the place where I live, and keep on working, of course!’ ”

Juan Valdez couldn’t have said it better.

A ceremony was filmed in a coffee grove. Sanchez, the previous Juan Valdez, greeted Castaneda, who was not yet wearing Juan Valdez regalia. “I present to you the accessories that I have used all my life,” Sanchez said, and he handed over the poncho, the hat and the reins of his mule, Conchita.

“In the moment, I felt a lot of happiness,” Castaneda recalls during a break from signing “Juan Valdez” autographs, posing for pictures and explaining coffee culture to tourists on the Mall.

It’s not a break from looking iconic, because he can’t help it. He’s like a Colombian John Wayne. His face is tranquil and strong at the same time, with pale green eyes.

“But in the moment I didn’t think of the responsibility that I had assumed. I only became conscious of the responsibility when I arrived back in my town — dressed as Juan Valdez.”

He rode on top of a firetruck.

“People were crying,” he says. “When I saw the multitude of people, so emotional in the streets, it was impressive. I said, ‘Oooh, wow.’ It gave me goose bumps.

“To fill the role of Juan Valdez is very big, it’s very beautiful. But more than anything, because I am a coffee grower, I feel it so much more.”

The role does pay better than growing coffee. Castaneda reportedly earned a typical coffee-growing income of $200 a month before he was named Juan Valdez. The growers federation does not comment on how much it pays him now. But Castaneda insists he has not lost his roots or simple lifestyle. He returns to work on the finca a couple times a month.

Most of the country’s 527,000 coffee-growing families belong to the growers federation. About one in three jobs in the countryside are in coffee. The average finca is slightly smaller than Casta­neda’s, and the picking really is done by hand. In that sense, Juan Valdez is an accurate image of a typical coffee farmer, and Castaneda is the spitting image of Juan Valdez.

“What holds a lot of things together in the countryside of Colombia is coffee,” says Juan Esteban Orduz, president of Colombian Coffee Federation Inc., a New York-based affiliate of the growers federation.

The nonprofit growers federation guarantees a base price to the farmers. The farmers are free to sell for a higher price to other buyers and exporters. The federation collaborates with the government and international funders on more than $300 million a year in development projects in coffee country, and seeks to expand the 20 percent of farmers who cater to organic, sustainable or other international niches, Orduz says. There’s also a chain of Juan Valdez cafes, including one at the corner of 19th and F streets NW, where coffee is served in ceramic cups.

Just in time for the Folklife Festival, late last month UNESCO added Colombia’s “coffee cultural landscape” to its list of World Heritage sites, calling it “an exceptional example of a sustainable and productive cultural landscape.”

On the Mall, Castaneda helps fellow coffee growers Jorge Ivan Valencia Londono and Jose Alexander Salazar Tapiero explain coffee’s journey from finca to coffee cup. He admires the coffee country hats being woven by 13-year-old Lida Isabel Hernandez Davila and her mother, Maria Dilia Davila Rios. He watches Jhon Jairo Amortegui Pina pop wheelies in a vintage American Willys Jeep, still used to haul sacks of coffee.

Mostly, Castaneda does the work of being Juan Valdez.

“As a Colombian it just makes me proud that he represents our country so well,” says Suranny Villamizar, a nurse born in Bogota, now living in Woodbridge, who has her photo taken with Castaneda. “I’m going to post this on Facebook and all my Colombian friends are going to be, ‘Oh, my God, that’s so exciting!’ ”

“Why didn’t you bring me a little cup of coffee,” teases Sofia Ochoa, a Colombia native who cleans houses in Alexandria.

“It’s the best coffee in the world, or no?” Castaneda says.

“For sure,” Ochoa says. “Listen, I lived in Costa Rica, and I couldn’t adapt to the coffee. I lived in Venezuela — even worse. I’ve lived here almost 30 years, and I only buy brands that say 100 percent Colombian. When I visit Colombia, I bring back 10 pounds.”

“Very good!” Castaneda says.