LAUSANNE, Switzerland - A gray-haired woman in her early 60s daintily lifts small trays topped with different varieties of marijuana to her nose, sniffing each of them carefully.

"Which one would you recommend for someone with medical issues?" she asks salesman Paul Monot, co-founder of the DrGreen shop in western Switzerland.

Posters of bright green cannabis plants advertise its wares, which, like those sold openly in a growing number of shops across Switzerland, are completely legal.

There is a catch however: They won't make you high.

"There is no psychotropic effect of our weed," says Monot, at his store in Lausanne.

On display are four varieties of legal cannabis boasting familiar names such as Skunk and Purple Haze, and an identical appearance and smell as their illegal counterparts.

Since 2011, cannabis containing up to one percent tetrahydrocannabinol - the component that gets recreational users high - can be sold and consumed legally in the wealthy Alpine country.

That compares to a 0.2-percent limit in most European countries, which effectively blocks all sale of cannabis flowers since crossbreeding plants to consistently contain below that level of THC has so far proved impossible.

Switzerland was eager to enable large-scale production of non-drug cannabis, especially to exploit another active component, cannabidiol, used in a range of products, from cosmetics to pet food, and increasingly valued for its potential health benefits.

It has taken years for the low-potency cannabis business to develop and demand to grow, but recently shops like DrGreen have been booming.

Monot and his partner launched in December and are already raking in sales of up to 100,000 Swiss francs ($99,500) a month.

Swiss media have cited estimates that sales of legal cannabis are currently about 100 million Swiss francs annually.

Trade really took off after health authorities in February ordered the low-THC cannabis be taxed like tobacco and carry similar health warnings, making it clear just how legal the product is.

"For the past month or so, it has just been exploding ... and we're surfing the wave," Monot told AFP.

Aziza, 37, said she only discovered a few weeks ago that legal cannabis was on sale in shops near her Geneva home.

"I love this stuff," she said, adding she had become increasingly concerned about the rising THC-levels in the illegal product she liked to smoke.

Agence France-Presse