17 May 2025

Researchers uncover giant 30-year-old fungus near Eltham

12:23 pm on 17 May 2025
From left to right Dr Peter Buchanan, (front),  Gerrie Viljoen, teacher at Ormiston Junior College, Auckland and Sam Lasham PhD student Auckland University (he's wearing orange, and was the person who found the enormous Ganoderma).

Clockwise from front Dr Peter Buchanan, Ormiston Junior College teacher Gerrie Viljoen, and Auckland University PhD student Sam Lasham. Photo: Supplied

A trio of fungal experts stumbled across the largest Ganoderma specimen they had ever seen during the annual New Zealand Fungal Foray this week in Taranaki.

PhD student Sam Lasham found the enormous Ganoderma bracket fungi, which was almost 82 centimetres wide and 45cm deep and thought to be about 30 years old, on a rotten stump at Rotokare near Eltham on Thursday afternoon, after a day of collecting.

Two others on the stump were almost as big.

He was accompanied by the academic leading the expedition, Dr Peter Buchanan from Manaaki Whenua Landcare Research, and Auckland teacher teacher Gerrie Viljoen.

Lasham said the Ganoderma was a perennial.

"It can keep growing out and down, but only if there's enough food behind it, on the stump that it's growing on."

But Buchanan said he had never seen one this size before in 45 years of looking, and estimated the fungus was about 30 years old.

Around 50 fungal experts and enthusiasts from across the country are taking part in the four day event, which ends Saturday.

Participants observed and photographed fungi in surrounding native forests, some of which are unlikely to have been previously studied for their fungi. The foragers have permission from iwi/hapū, the Department of Conservation and Taranaki Council to collect them.

Several of the forests being accessed during this Foray are unlikely to have been previously studied for their fungi.

Orange pore fungus Favolaschia calocera.

Orange pore fungus Favolaschia calocera. Photo: Supplied / Kim Triegaardt

Fungus of the Year 2025

This year's foray includes a "Fungus of the Year" promotion with 12 fungal candidates to vote from.

People can vote for their favourite fungus, or maybe vote for a fungus that is threatened, or culturally important, or edible, or (on the negative side) one that's causing an important disease. As a Kingdom entirely separate from plants, and more closely related to animals, fungi come in so many shapes, colours and forms.

On the specimen table at the Fungal Foray.

On the specimen table at the Fungal Foray. Photo: Supplied / Kim Triegaardt

Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.

Get the RNZ app

for ad-free news and current affairs