Erin Patterson is accused of intentionally offering a toxic beef Wellington to her ex-in-laws, Don and Gail Patterson, aged 70, and Gail’s sister, Heather Wilkinson, 66, as well as Heather’s spouse, Ian Wilkinson.

Ian Wilkinson was the only lunch guest to survive the July 2023 meal.

Patterson claims the poisonings were a terrible accident.

Today, two mycology specialists from Victoria’s Royal Botanic Gardens provided the jury with insights regarding death cap mushrooms, including the leading scientist who scrutinized a sample of the said beef Wellington.

Mycologist Camille Truong was working on-call for the Victorian Poisons Information Centre on July 31, two days after the meal, when she received a call from Monash Hospital toxicology registrar Laura Muldoon.

Dr Muldoon told her there were four patients who had been hospitalised after consuming a meal that contained mushrooms and she asked for Dr Truong’s help to identify the mushrooms, she told the jury.

She sent Dr Truong photos of the meal’s remains, which the jury earlier heard had been seized by police from a bin outside Patterson’s home in Leongatha and transported to Monash Hospital in Melbourne.

But Dr Truong said she could not identify them from the photos, and Dr Muldoon arranged to deliver the sample to the Royal Botanic Gardens national herbarium for her to analyse.

Dr Truong left work early that day and the package containing the meal’s remains was delivered about 5pm.

A colleague brought the beef Wellington sample to Dr Truong’s home, where she analysed it under a microscope.

“Did you find any death cap mushroom pieces?” prosecutor Nanette Rogers SC asked.

“I didn’t,” Dr Truong replied.

She put the remains into her fridge overnight and took them into the Royal Botanic Gardens the next day where she re-examined them under another microscope.

“I pulled out all the little pieces of mushrooms on a tray, I also took photographs,” Dr Truong said.

But she again did not find any sign of death cap mushrooms.

“The mushroom I identified is the field mushroom – this is the typical mushrooms you find in the supermarket – that’s the only mushroom I found under the microscope,” Dr Truong said.

She said a Department of Health representative arrived about 1pm on August 1 and collected the food sample.

Earlier, defence barrister Sophie Stafford discussed a coronial report about a woman who died in May 2024 after making herself a meal out of mushrooms picked from her garden.

The elderly woman died from death cap mushroom poisoning, the jury was told.

Mushroom expert Thomas May said Victoria’s Department of Health had contacted him about the recommendations, which included that more public health messaging was needed on the dangers of consuming wild mushrooms.

Before he was excused as a witness, Dr May was asked by the prosecution’s Dr Rogers about the smell of death cap mushrooms.

“I have tried death cap mushrooms on a number of occasions and I find the smell to be particularly unpleasant,” he replied.

The trial before Justice Christopher Beale continues.