A Giant Fungus in a Family of Its Own
Fifty centimetres tall, 2.2 kilograms, and a lineage that starts as the dinosaurs exit.
Dianjunus rex grows upright fruiting bodies up to 50 centimetres tall and 2.2 kilograms. That is the largest known fruiting body in the Ascomycota, the sac fungi. It is not a new species tucked into a familiar genus. A team at the Kunming Institute of Botany places it in a new genus and a new family, Dianjunaceae, within the Xylariales. A molecular clock puts that family near 65 million years ago. The paper is in Frontiers in Fungal Biology. CNN reported the find on 23 October 2026.
Farmers around dying oaks in Yunnan had already noticed the pale fingers. Some had tasted them. That is not a safety study, and it is not a mystery in the paranormal sense. It is a reminder that a whole family of fungi can sit at the edge of a field and wait for a survey.
Key Evidence
- Frontiers in Fungal Biology description of Dianjunus rex
- Up to 50 centimetres tall and 2.2 kilograms
- New genus and new family, Dianjunaceae, in the Xylariales
- Molecular clock: family near 65 million years ago
- Found in a 2024–2025 survey around dying cork oaks in Yunnan
- Kunming Institute of Botany; EurekAlert release; CNN, 23 October 2026
The Rational Explanation
Size is not a paradox. Fungi already include organisms that are mostly underground and occasionally embarrassing to a measuring tape. The oddity is taxonomic. A family missed until a recent survey is a comment on where mycologists have and have not walked, not on the laws of growth. Local use is evidence the thing is conspicuous. It is not evidence it is edible.
What We Don't Know
Whether the 65-million-year figure holds once more genomes are in the clock. How widespread the fungus is outside the oaks in the survey. What, if anything, the association with dying trees means: cause, passenger, or coincidence. And whether anyone should be eating it. The paper is a description, not a menu.
The Rabbit Hole
The largest organisms on Earth, by some measures, are fungi: a honey mushroom in Oregon covers kilometres and is mostly invisible. Dianjunus is the opposite kind of giant. It is small by that standard and enormous by the standard of its own phylum, and it stands in the open. The king fungus that taxonomy walked past is a better headline than any curse attached to it.