If you go into the woods today – be aware of toxic mushroom species

Foraging for wild food has become increasingly popular but comes with a warning of life-threatening consequences. Emma Hildesley talks to foraging expert and author Peter Langlands about how to stay safe when you're searching for food.

Autumn is the time of year when mushrooms begin to pop up in shady nooks and crannies across the country, prompting fresh warnings from experts about the importance of foraging carefully.

Foraging refers to the act of searching for free food from nature, often in public or wild areas. It's seen a boost in popularity in recent years, due to both its money-saving and eco-friendly advantages (no plastic wrap!). And also because it's been promoted by countless influencers on social media platforms like TikTok.

Christchurch-based marine and freshwater conservationist Peter Langlands was foraging long before it was fashionable. His ecological obsession began, he says, with a childhood interest in ornithology (the study of birds), and branched into a lifetime love affair with the outdoors.

After completing his studies in natural sciences and zoology at Canterbury University in 1993, Langlands began to explore the practice of foraging for food, later building up a following with his Facebook page Wild Capture, sharing with others how to safely collect edible wild foods including fruit, fungi and seaweed. Now he has literally written the book on the topic, with Penguin NZ bringing out a weighty tome called, simply, Foraging, next week.

Finding food in the wild may seem like an infallibly wholesome pursuit but Langlands warns that foraging – particularly for wild mushrooms – is not without its risks.

"You've definitely got to be very careful with foraging and there are definitely a range of deadly, poisonous species out there," he said.

"You have to be 100 percent sure of what you forage and just take your time and just accurately identify everything. You sort of do take your life into your own hands when you go out foraging, but that's sort of the excitement of it," he laughs.

He recommends attending a course to better understand distinguishing features of an edible vs non-edible mushroom and work on correctly identifying something different each time you venture out to build a strong knowledge base.

He describes the process of identifying mushrooms as a "progressional thing," recommending people work through a process of deduction to confirm what things are.

But even if you feel confident that you've accurately identified an edible mushroom, Langlands doesn't advise frying up a big plate of them and digging in. "[When] eating a new food [it] does pay to try a small amount," he says.

And according to the NZ Poisons Centre, you should never trust Google or an app when attempting to identify a species. They tend to be Northern hemisphere oriented and the visual differences between a toxic and non-toxic plant can be very subtle.

Knowing which varieties of mushrooms (or other plants) to eat or avoid is essential, but it's not the only thing, says Langlands. "Be aware of the environmental quality of where you're foraging. Environmental factors such as the quality of the soil, knowing information about the site where you're foraging, and historical land use changes, because a lot of areas of flat land around urban environments historically were landfill sites."

Even "non-toxic" wild mushrooms can sometimes cause poisoning due to factors like the presence of heavy metals in the soil.

Death cap mushrooms were thrust into the spotlight last year following the poisoning deaths of three people who'd attended an ill-fated lunch party in Victoria where mushrooms were served in a beef Wellington. Their deaths were said to be consistent with death cap mushroom poisoning, although their host, Erin Patterson, claims to have purchased them at an Asian grocery store.

Australia's food safety information council issued a particular warning last month about the lethal dangers of mistakenly ingesting death cap mushrooms, or Amanita phalloides, which look alarmingly similar to standard mushrooms people can buy in the supermarket.

"Apps and Google are not reliable to identify mushrooms accurately as they often only recognise Northern Hemisphere mushrooms and mushrooms change appearance during their growth cycle," Australia's food safety information council chair Cathy Moir told 9News.

The death cap species typically grow around the base of oak and chestnut trees following rainfall and are responsible for around 90 percent of mushroom-related deaths globally.

While they can be found in a few regions of New Zealand, Langlands said they are not common.

"The deathcap is certainly one to be aware of, but it's actually very rare in New Zealand. So it's a mushroom most people won't encounter. I've never seen one personally," he says.

However that's no reason to relax when foraging. According to the NZ Poisons Centre, there are many different species of poisonous mushrooms in Aotearoa and a lot of those look "remarkably similar" to ones that are safe to eat. "Even tiny amounts of some mushrooms can cause serious poisoning," warns the site.

Langlands says the popularity of foraging is exciting because it's a chance for people to both get outdoors and to disconnect from digital technology.

"It's a real life experience for people and gives a feeling of food sovereignty and empowerment.

"There's also a lot of health benefits and I think we're seeing the mainstream food system becoming a lot more processed, losing a lot of diversity and also it gives people a feeling of food resilience.

However, he said online groups can make it difficult for first-time foragers to correlate what they're seeing online with what they're about to ingest.

"Social media is a very confusing and messy space. It can help in some ways, but it's really good just to have a comprehensive book," he said.

And despite the need for caution, Langlands is still a huge proponent of foraging and the growing excitement around it, not least for the "diversity of favours" it offers. "Certainly from a culinary point of view, it expands out the whole platform of what is available."

For a freshwater and marine expert, Langlands spends a lot of time in the bush. "I've done quite a lot of fishing... and the good thing with plants is they can't swim from you or get away from you."