Early each morning at La Flor de Puebla bakery, on Kenilworth Avenue in Riverdale, customers line up for hot bolillos -- loaves of crusty sandwich bread with a soft, chewy center.

On sunny summer afternoons, these same folks know that they can cool off with tamarind-, pineapple- or lime-flavored shaved ice at the gaily striped helado cart outside the El Rodeo country western store on nearby Annapolis Road.

As the sun sets over a shaded, vacant lot on Edmonston Road, the tacos-to-go truck opens for business.

There is no shortage of great, tacos or the essential ingredients to make them in the neighborhood known as Little Mexico. Along a one-mile stretch of Kenilworth Avenue and on adjoining streets, a little more than a mile from the District line in Prince George's County, a Mexican community has emerged.

Over the past four years, a growing number of Mexican restaurants, markets and bakeries have opened in a relatively small area, in and around Riverdale, giving the Washington region an opportunity to taste traditional dishes from southern Mexico. "The [Mexican] people found a less expensive neighborhood, got their foot in the door and changed the neighborhood. Now, this area is really cooking," says Paco Lubian -- whose father, a native of Cuba, opened Americana Grocery on Annapolis Road in 1993.

Anchoring one end of the Bladensburg Shopping Center, Americana is a fairly large market with a mix of Latin American, African and traditional American products. Of particular note is the custom-cut butcher counter. In addition to oxtail and beef feet for soups, the counter has a terrific selection of sausages from Central and South America. But the Mexican influence is even stronger around the corner.

At El Tapatio restaurant in Bladensburg, spangled black velvet sombreros hang on walls painted two tones of purple. The festive, lipstick-red oilcloths on the tables are illustrated with mini-mariachis and cactuses. At 4 p.m., on a weekday, the place is jumping.

"That's when the men get off work," says Elizabeth Navarro after delivering to the table a tall glass of horchata -- a sweet, rice-based drink flavored with vanilla. According to Navarro, many of these workers live in group houses, four or five together, and don't cook, so they come to the restaurant for their meals. Her family owns both this restaurant and another in their hometown of Guadalajara. Both specialize in barbecued goat.

"Nobody was doing goat when we opened 31/2 years ago. Nobody," she says with a shake of the head. "Back home ,our goat has won competitions for generations."

But the mostly male crowd has ordered large bowls of a tomato-based shellfish soup -- caldo de mariscos -- a favorite in southern Mexico. No one is talking. No one can. The jukebox is blasting Mexican dance music. Back in the kitchen, Navarro's father, Ruben, assembles each soup as it's ordered.

"You might have to wait 15 minutes. We don't have soup made up," he says while transferring steaming mussels and clams into an empty bowl. El Tapatio is also noted for its flavorful, handmade, white corn tortillas.

Such tortillas, whether handmade or factory-made, are the foundation for the soft taco -- the most prevalent dish in Little Mexico. These tortillas are thin, light discs, and it takes two of them, overlapping, to hold the ingredients of the soft taco. They are sold at restaurants, at cafes called taquerias and from roadside trucks.

For the typical beef soft taco, bite-sized chunks of marinated, grilled, skirt steak are piled on two layers of tortilla. On top goes a sprinkle of cilantro and a little chopped red onion. Sliced radish and wedges of lime or lemon are served alongside.

At the fairly subdued, blue-tiled Taco Rico taqueria, which opened in January on Edmonston Road, there is a choice of tacos ($2 each) made with beef, beef tongue, pork, goat or sausage. Each is seasoned in a unique way.

"Up north [in Mexico] it's all Tex-Mex. But I'm from Puebla state down in the south," says owner Myrna Luna. "What we do is use more kinds of chilis and more dried spices." For Luna's pork taco, for example, the well-cooked, pulled meat is heavily seasoned with a chili powder blend. But there is more chili flavor than chili heat.

Blocks away at La Sirenita restaurant, festooned green and white filigree paper pennants create a party-in-progress atmosphere. But what's a party without entertainment? A few weeks ago on a Thursday evening, a young guy pulled the plug on the jukebox, grabbed his guitar and let loose with a Mexican-styled version of the early 1960s Highwaymen hit "Cotton Fields," complete with a whistle chorus.

La Sirenita's shrimp cocktail turns out to be a snappy, fresh-tasting gazpacho with plump, medium-sized shrimp and sliced avocado, served in a tall ice cream sundae glass. Deep-fried quail comes with an assertive green chili sauce. And while the typical cheese quesadilla in the Washington area is a flat, grilled tortilla that sort of resembles a white cheese sandwich, here it's more of a fried, folded affair -- the cheese tangy, the tortilla crisp, the whole business drizzled with a cream that's tart and sour.

More predictable Mexican food, such as steak fajita and burrito combination plates, can be found at the spacious Alamo restaurant and lounge back on Kenilworth Avenue in Riverdale. Alamo turns 50 years old this month. Located in Plaza del Alamo, a Spanish-style strip mall with a terra cotta tile roof, the present owners have brought in new landscaping and refurbished the softly lit interior with comfortable, upholstered booths. Derek Crossley is the manager.

"We want to be upscale for this neighborhood and improve the community," says Crossley, who has added a lobster taco to the menu as well as specials such as chili-crusted, pan-seared scallops with a citrus vinaigrette. He came up with 15 salsas using different chili peppers. In the pine-paneled Alamo lounge, more than 60 different kinds of tequila are available -- from a sharp, peppery Sauza Reposado at $7 a shot on up to $40 for a shot of exceptionally smooth Don Julio 1942.

Danilo Mejia, a native of Honduras, opened Pollo Fiesta on Kenilworth Avenue in April. Peruvian-style chicken is the house specialty. But most of the menu is solidly Mexican. "The chicken enchiladas are wonderful. But if you're watching your carbs, get the [Peruvian] chicken and salad. If you're not, include the rice and beans, because they are really good," says customer Bernice Friedlander, a program analyst at the Food and Drug Administration's Center for Food Safety and Applied Nutrition in College Park.

Not far from Fiesta, along Kenilworth, is the La Flor de Puebla bakery. Apparently, most shoppers know the drill. Just inside the door there's a stack of plastic trays as well as tongs. Baker's carts loaded with loaves of fresh bread are wheeled to the center of the sales floor, and shoppers grab the tongs and choose their favorites. The most popular sweet bread is the concha -- a yeasty bun covered with swirls of colored, flavored sugar. Around the noon hour, La Flor bakers make torta sandwiches, filling the bolillo loaves with stacked combinations of ham, cheese, avocado, tomato and onion. They sell for $3 each.

The Little Mexico neighborhood market with the most overall appeal is El Primo Grocery on Edmonston Road. As markets go, it's small, no larger than a two-car garage. Aisles are narrow with barely enough space to pass another shopper. But little El Primo makes up for its compactness with a super selection of dried chili peppers, from the plump, mild-flavored, fist-sized poblano to the sweet, smoky-tasting and decidedly hot pequin entero that is no larger than a fingertip. When a recipe calls for uncommon fresh fruits and vegetables such as sweet mamey or garlicky guaje (see facing page) they can often be found, in season, in El Primo's produce department.

In a back corner, a wall is covered with dried herbs and spices imported from Oaxaca -- a revered center for traditional foods in the mountains of southern Mexico. For example, dried avocado leaf is added to black bean dishes or a chicken stuffing. A sprinkle of epazote brings a distinctive flavor to a chicken tortilla soup. On a shelf devoted to spicy chili sauces, one brand is the bestseller -- the versatile Valentina Salsa Picante.

"For me, it's great on sliced cucumber or I put it on popcorn," says owner Cruz Guzman, who opened El Primo three years ago. She says her store's meat department is noted for thin-sliced, marinated pork shoulder "perfect for a taco or enchilada." Cuzman and her family are putting the finishing touches on a taco restaurant, right next door, that they hope to open in the weeks ahead.

Concentrated flavors: At top, selling nopal cactus at El Primo Grocery; a double stack of thin white corn tortillas is a must for the chicken and beef tacos at El Tapatio restaurant on Kenilworth Avenue; making white corn tortillas by hand at El Tapatio; El Primo's storefront on Edmonston Road. * WHAT YOU'LL FIND IN LITTLE MEXICO, AND WHERE IT IS PAGE 5 * FIVE UNUSUAL FRUITS, HERBS AND VEGETABLES YOU CAN GET THERE PAGE 5El Tapatio's caldo de mariscos (shellfish soup) comes together; at right, tacos de carne asada are ready to go.Conchas cool in the racks at La Flor de Puebla bakery on Kenilworth Avenue in Riverdale; below, uncommon produce at El Primo Grocery on Edmonston Road.