Carefully, Wolfgang Bivour emptied a basket full of colorful mushrooms on the forest floor and put the fungi in long rows next to each other.

There were delicious-looking porcini and brown-capped bay boletes, slimy-purple brittlegills, honey-colored armillaria, and green death caps — which are Germany's most poisonous mushrooms.

Bivour, one of Germany's most famous fungi connoisseurs, was surrounded by a group of 20 people listening attentively to his lecture about the many different species they had just collected on a tour through an oak and beech forest on the outskirts of Potsdam in eastern Germany.

Mushroom hunting — which was a pure necessity in the years after World War II, when starving people were scouring the forests for anything edible and then mostly forgot about it when the economy started booming in the 1950s — has seen a big comeback in Germany in recent years.

Triggered by the coronavirus pandemic, when many people went hiking outdoors to escape their cramped apartments, vegan lifestyles encouraging the consumption of mushrooms, a growing interest in the use of medicinal fungi, and the viral spread of mushroom pictures on social media, the hobby has become a chic lifestyle pastime in Germany.

For 75-year-old retired meteorologist Bivour, his mushroom tour is not simply "about filling your basket" but more essentially "about teaching people about the importance of mushrooms in the ecosystem and, of course, about biodiversity, with the mushrooms that you find."

Bivour, who has been giving mushroom tours in the Potsdam region southwest of Berlin for more than five decades and is also called up by hospitals to advise if there's a suspected case of mushroom poisoning, knew every mushroom the people picked and showed him.

He let them smell and taste the fungi, talked about their healing powers or toxicity, gave suggestions on how to prepare some of them, and offered historical anecdotes on others.

The mushroom expert said he, too, had noticed the rapidly growing passion for his longtime hobby.

During fall time, experts like Bivour often offer their knowledge on weekends at markets or community colleges where people can come, show their bounty and make sure they hadn't accidentally picked poisonous mushrooms.

Indeed, many people in Germany are afraid to accidentally pick poisonous mushrooms.

While the poisonous red-capped, white-dotted fly agaric can be easily identified, the very toxic green death cap is sometimes confused with the common button mushroom, or champignon, which is the most widely sold mushroom in stores across the country.

Each year, several people die from eating death caps.

In Germany, the porcini and bay boletes are often simply fried in butter and offered on toasted sourdough bread with salt and pepper.

Margit Reimann, who participated in the tour with her mother, said she was surprised to learn from Bivour how many more mushrooms than she thought were edible.

However, despite the newly acquired knowledge, she said, she'd stick to the familiar ones when going out to the woods with her kids next time.

AP video shot by: Pietro De Cristofaro