They once were hawked on street corners, displayed like the finest artwork with their images of Aztec warriors, Virgin Marys, lions, pandas and unicorns.

Laura Genao saw them growing up but never pictured herself owning one.

“Too tacky,” she thought.

Years later, her mother slyly left one on her couch: a blanket with a giant tiger woven in shades of gray, black and white.

It was then Genao learned: Love it or hate it, chances are you’re going to forge a bond with a San Marcos.

The thick, plush Mexican blankets with designs of everything under the sun, including the San Francisco 49ers logo, Strawberry Shortcake, peacocks and geishas, have kept Latinos warm for nearly 40 years.

They’re so popular that they double as bedspreads, sofa slipcovers, car seat covers, wall art, curtains, rugs and even ponchos. They’re a gift often given for Christmas, birthdays and baby showers. When a grown child is ready to leave home, a San Marcos usually goes along.

Genao got her tiger soon after she graduated from law school. Her mother considered it an upgrade from thick, plaid Mexican blankets and something more suitable for a professional.

The attorney resisted for a few weeks, but she decided to give the blanket a try.

“It was the warmest, most comforting thing in the world,” Genao, 42, said. “It reminded me of family and of my mom.”

When she wrote about the experience on her blog, responses flooded in. People across the country — in Texas, Illinois, Missouri — wrote in to boast and reminisce about their own San Marcoses.

“In my family it’s a must that we all have our own cobija San Marcos.”

“My old wolf San Marcos is threadbare after 30 years.”

“That blanket has gone everywhere with me in life. If it could talk!”

The famous Mexican cobija, or blanket, is often a running joke among the thousands who own them, a likely contender for any list of Top 10 Things Latinos Love.

“It’s like a black velvet Elvis,” says Rafael Cardenas, of East L.A., who’s accumulated four blankets of his own. “It’s so cheesy, but you’re proud of it, you’re nostalgic over it because it’s your culture.

“If you sit at a table with any Mexican anywhere and say, ‘Hey, remember the San Marcos blankets?,’ they’ll know exactly what you’re talking about.”

Tributes to what’s been called the original Snuggie abound online: on Facebook, YouTube, blogs and forums.

In 2003, urbandictionary.com added the San Marcos to its list of streetwise lingo. Definition: Pimpin’ warm blankets from Mexico. As in: “Hey vato, bring the San Marcos to the carne asada in Delano manana.”

First produced in 1976, the San Marcos ceased production in 2004. That only made Latinos want them more.

Francisco Rivera isn’t at all surprised.

His brother, Jesus Rivera Franco, created the San Marcos 36 years ago. The son of a sombrero-maker was a tiny man with snow-white hair and a large belly by the time he died in 2009 at age 91.

He started making serapes at age 12 in Aguascalientes, in central Mexico. At 20, Jesus and his family opened their own business making scarfs, shawls and blankets — striped colorful ones popular in the 1930s. He eventually opened his own factory.

In the mid-1970s, he began to look for ways to create a new kind of blanket.

“His dream was to come up with one that would last, that every Mexican would love,” Rivera, 73, said.

He found it during a trip to Spain: a warm but not too heavy cover made of acrylic with a thick border and images repeated on both sides in reverse colors.

Jesus returned to Mexico, determined to reproduce it. It took about five months and more than 2,000 tries. He called the blanket the San Marcos, after his neighborhood in Aguascalientes.

As soon as it hit the market in Mexico, it was a success. “Everybody wanted one,” Rivera said.

Soon, Jesus’ workers were producing 300,000 a month — in twin, queen and king sizes, as well as a crib version. Buyers gathered at high-end hotels in Mexico City to see Jesus’ latest designs, created by artists in Spain. The first ones sold for as little as $8.

His success changed the face of Aguascalientes. Jesus eventually had six factories, employing more than 8,000 people. He built shopping centers, office plazas, housing developments, a school and a convent. A road on the south end of town bears his name.

Mexicans living in the U.S. swooped into Tijuana to buy his blankets in bulk.

“One morning, we delivered a huge truckload with at least 5,000 blankets,” Rivera said. “By the afternoon, they were gone.”

In 1993, Jesus sold his business to a company in Monterrey, Mexico. Sales were good for a few years, but then knockoffs from Asia — Koreanas, as they’re known among Latinos — began to flood the market.

The company in Monterrey struggled; in 2004, after six years of poor sales, it stopped producing the famous blanket. Mexican newspapers announced its demise: Goodbye, San Marcos blankets. The tradition of the San Marcos blankets has come to an end.

Lucia Torres, 32, of Highland Park, still has an original blue-and-black San Marcos she got when she turned 10. It’s worn, falling apart at the edges, but it never leaves her bed. It reminds her of lazy, rainy mornings when her mother was in the kitchen humming songs and making tortillas.

“Now that I’m older, I have so much to deal with,” said Torres, a project manager for a nonprofit. “But at the end of the day I know I can always go home, crawl into bed and throw my blanket over my head.”