A 'four-fingered' yam, over 70 centimeters long and weighing 14.6 kilograms, has recently been harvested by a farmer surnamed Chen in Zhongjiang county, Sichuan province.

Chen said he had discovered a green seedling in his backyard last spring and was surprised when he dug out the plant.

"I've never fertilized or watered it and didn't expect it to grow this big," he said.