An agricultural expert has called for stricter controls on the harvesting of wild rhododendrons after an online sales boom caused a large number to be cut down in Heilongjiang province.

More than 190 stores on Taobao, the country's biggest online shopping platform, sell rhododendron branches, priced from 10 ($1.45) to 30 yuan each.

They are advertised as flowering for up to four weeks if put in water and have even been claimed to have air-purifying qualities.

According to a newspaper in the?Daxinganling prefecture of Heilongjiang, where many of the plants originate, one Taobao shop sold more than 190,000 rhododendron branches in a single month earlier this year.

But the rush to harvest the wild plants has caused scenes of devastation.

Footage that has been circulated on social media shows a road in the area carpeted with discarded cuttings from the plants, with many being pulled up by the roots.

"The booming business in these flowers must have triggered a mass cutting, which has devastated the province's stock," said Zhu Ning, a professor at Northeast Forestry University, in Harbin, capital of Heilongjiang.

"There should be strict controls to stop all this cutting and selling before it's too late."

Zhu said wild rhododendrons grow at a rate of about 10 centimeters per year and cannot recover quickly from being chopped down en masse.?