According to a study published on Tuesday, the cactus plant is the fifth most threatened species in the world, Christian Science Monitor reports.

"The results of this assessment come as a shock to us," lead author Barbara Goettsch in a release by the University of Exeter.

"We did not expect cacti to be so highly threatened and for illegal trade to be such an important driver of their decline."

The study shows that cactus is among the "most threatened species," because 31 percent of cactus species are near extinction. The study attributes the decline to cattle ranching and illegal trade in cacti.

Cactus are the fifth most-threatened species in the world, according to a global survey of threatened species published by the International Union for Conservation of Nature Tuesday in the journal Nature Plants.

The news is disturbing, Inger Andersen, IUCN's director general told Reuters.

"They confirm that the scale of the illegal wildlife trade, including trade in plants, is much greater than we had previously thought," Ms. Andersen.

The decline in the species of cacti will have a direct impact on America's ecosystems. They are also essential for the survival of many animal species, as they provide a source of food and water for many species including deer, woodrats, rabbits, coyotes and turkeys. Cactus flowers provide nectar to birds, bats, bees, moths and other insects.

"Because of the booming market for desert plants used in landscaping, and over enthusiasm by private collectors, we are running the risk of losing certain species," says Christopher Robbins, a botanist and author of "Prickly Trade," a new report by the World Wildlife Fund in Washington.

The Chihuahuan Desert is home to almost a quarter of the 1,500 cactus species known to science.