Lethal death cap mushrooms are beginning to return to Victoria for the summer.

The fungi pop up in the capital city and around Vancouver every year, usually around August.

Experts on Vancouver Island said a couple stumbled on a cluster of deaths caps in the Uplands near Victoria on Sunday, the first reported sighting of the season.

"The reason I think we're seeing ... them in the Uplands area this year, it's a very lush green area where they like to water their lawns. The mushroom is stimulated by moisture underground," said Dr. Brenda Callan, a mycologist with Natural Resources Canada.

She said death caps contain a number of toxins, including amatoxin, which even survives cooking. One mushroom can kill an adult.

Paul Kroeger hand and death cap

Paul Kroeger holds up young Amanita phalloides or 'death cap' mushrooms, which can resemble puffballs or straw mushrooms. This bunch was found near Main Street in Vancouver in 2016. (Tristan Le Rudulier/CBC)

Callan said death caps have some telltale characteristics that set them apart from other fungi, including a greeny-bronze colour to the cap, a veil around the stem, white gills and a large bulb under the ground.

They look similar to puffball or paddy straw mushrooms, which are popular in Asia.

Anyone with children and pets needn't panic, but just be alert, Callan said.

"Be aware that they're present, that all attractive mushroom aren't edible. If somebody is trying to pick and eat mushrooms for the first time, stay away from city areas and stay away from anything that hasn't been verified by an expert ... don't take any chances," she said.

Last year, a three-year-old boy died after accidentally eating one of the mushrooms while he was out foraging with his family. It was the first recorded death from a death cap mushroom in the province.