New family of fungi found in Yunnan produces one of the world's largest fruiting bodies

Chinese scientists have discovered a new family of fungi whose first known species produces one of the world's largest fruiting bodies.

Researchers from Kunming Institute of Botany under the Chinese Academy of Sciences, found the giant fungus during fieldwork in the forests of southwest China's Yunnan Province.

Named Dianjunus rex (D-rex), the fungus produces large, fleshy reproductive structures up to 50 centimeters tall, including its underground stalks. An exceptionally large, two-lobed specimen weighed 2.2 kilograms.

The name reflects both the fungus's origins and its massive size. "Dian" refers to the ancient Dian kingdom in what is now Yunnan. The Latin word "rex," meaning king, also appears in the name Tyrannosaurus rex.

The findings, published in Frontiers in Fungal Biology, highlight how much of Yunnan's fungal diversity remains unexplored. Researchers have documented about 6,000 fungal species from the region, but the estimate is roughly 104,000.

The fungus is believed to grow from the roots of recently deceased trees and the surrounding soil. It's the largest known fungus in the phylum Ascomycota, the largest fungal phylum, which contains roughly two-thirds of all described fungal species.

Its reproductive structures, called stromata, are covered in a white, powdery, fibrous coating when young. As the fungus matures, the surface darkens to a dull yellow. The top is blunt and rounded, like a bulb of garlic. Finger-like branches grow out of it as it develops. Inside, the flesh is solid and spongy and is cream to yellow in color. It has no strong smell and no noticeable taste.

DNA analysis suggests D-rex first appeared about 65 million years ago, shortly after the mass extinction that wiped out roughly three-quarters of Earth's plant and animal species and ended the reign of Tyrannosaurus rex.

The researchers think the timing may be more than coincidence. After the extinction, ecosystems were in disarray, and many living spaces sat empty. This fungal lineage may have moved into those gaps as the forests grew back.

(All photos via Kunming Institute of Botany, Chinese Academy of Sciences)