PHILADELPHIA: It would be easy to lose track of time amid the 10 acres (4 hectares) of horticultural fantasy at the Philadelphia Flower Show. But don't worry - Big Ben is there to keep you on schedule.

A truncated version of perhaps the world's most famous clock is the centerpiece of the floral spectacular that opens Saturday. This year's event boasts a British theme that examines horticulture from urban London to rural cottages. And it's summed up by a single Anglicism: "Brilliant!"

"It basically means 'awesome' in American terms," said Drew Becher, president of the Pennsylvania Horticultural Society, which sponsors the show. "We have really transported Britain to Philadelphia - to America - for the next 10 days."

Indeed. Visitors enter through giant "royal" gates and stroll along an avenue lined with white birch trees before arriving at the 38-foot-tall (11.5-meter) Big Ben. The timepiece towers over terraces filled with varieties of English roses; its four faces are screens that will display a clock as well as offer light-and-sound shows every half-hour.

Major exhibits include the crown jewels rendered in flowers and set amid a Tower of London tableau; a manicured cricket club; a 1960s "peace garden" inspired by the British music invasion; the Mad Hatter's tea party; and the dreary streets of 19th-century London, as roamed by Jack the Ripper.

A stylized display titled London Fog blooms with calla lilies, mother-of-pearl roses and French tulips. As a light "drizzle" falls on flower-bedecked umbrellas - some dangling from the ceiling, others clustered in vertical stands - "fog" swirls below.

"We have a mist and a gentle rain and lots of black umbrellas to give you the flavor of a London scene," said Robin Heller, co-owner of the Flowers by David, the Langhorne, Pa.-based company that designed the scene.

Stoney Bank Nurseries took a more rural path with its version of Hidcote Manor, a property in the Cotswolds once owned by a prominent plant collector. The exhibit uses hundreds of perennials like lupines, delphiniums and irises to re-create "the epitome of the Arts and Crafts garden," which favored natural plants in less formal arrangements, nursery co-owner Joe Blandy said.

More than 270,000 people are expected to converge on the Pennsylvania Convention Center for the event, which runs through March 10. Billed as the world's largest indoor flower show, it's also one of the oldest, dating back to 1829.

The event includes plant judging, workshops, lectures and floral arranging competitions. A "British Village," featuring U.K. vendors and merchandise, will exhibit photos of the royal family's many visits to the Chelsea Flower Show in London.

Chris Woods, who designed the grand entrance installation in Philadelphia, was born and raised in London before coming to the U.S. in 1981. He described gardening as a national pastime in his native country, and noted it is quickly becoming one in America as well.

"It's regarded not only as a hobby in England, but a legitimate art form," Woods said.