Amanita phalloides or Death Cap Mushrooms Spreading in BC

Amanita phalloides or the death cap mushroom is said to be the deadliest mushroom in the world. Unfortunately, it’s spreading in British Columbia. Ingestion of the mushroom initially causes gastrointestinal symptoms, which last for around twenty-four hours. The patient may then start to feel better. This stage is known as a false recovery phase, however. The fungal toxins harm the liver and kidneys, which may lead to death. It’s very important to avoid eating the mushroom.

The photos and fungus description in this post are included for general interest only. They are not meant to help anyone identify mushrooms. A particular mushroom may have a different appearance from other members of its species, change its appearance as it ages, or have features that make it easily confused with another species. The death cap can be confused with edible species. Mushrooms must be identified by an expert.

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Amanita phalloides; photo by H. Krisp, CC BY 3.0 License

Mushrooms are the reproductive structures of certain fungi. The vegetative part of a fungus consists of branching, thread-like structures known as hyphae. The hyphae extend through the substrate of the fungus, forming a mass called a mycelium. They secrete digestive enzymes into the substrate. These digest suitable food into nutrients, which the hyphae absorb. Fungi aren’t plants and can’t make their own food in their bodies as plants do, so they must obtain chemicals from their environment in order survive.

The death cap is classified as an ectomycorrhizal fungus. An ectomycorrhiza in an association between the roots of a plant and the hyphae of a fungus. Hyphae of soil fungi enter the roots and surround its cells. The relationship is beneficial for both organisms. The fungus is able to absorb food that the plant has made and the plant absorbs water and minerals that the hyphae have obtained from the soil.

Amanita phalloides is native to Europe and not to British Columbia. It’s believed to have arrived in the province in the roots of imported plants. It associates with oak, hazel, beech, hornbeam, sweet chestnut, and other trees. It may now be spreading via the planting of trees from plant nurseries in landscaped areas, parks, and gardens.

At the moment, the fungus is found mainly in or near to urban areas. Investigators fear that it could soon spread to forests. In Victoria (British Columbia’s capital), the fungus has become associated with some native Garry oak trees.

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The death cap mushroom; photo by Stu’s Images, CC BY-SA 3.0 license

The mushroom is first visible as a small whitish ball emerging from the ground. The ball is known as the button stage. It’s covered by a thin layer of tissue called the universal veil. People may mistake this stage for puffballs, some of which are edible. Cutting the button stage open should reveal the immature parts of the mushroom and show that it’s not a puffball. When the mushroom is slightly older, it may be mistaken for straw mushrooms or paddy straw mushrooms, which are popular in Asian cuisine.

As the stem breaks through the outer covering of the button and elongates, a sac called the volva is left around the base of the stem. When the cap expands, the covering over the mushroom’s gills breaks, leaving a ring of tissue around the stem called the annulus. The cap has a range of colours. It may be white, pale yellow, dark yellow, brown, or even green.

In southwestern British Columbia, the mushroom is generally seen from June to November. This doesn’t mean that a mushroom seen in other months couldn’t be a death cap. Nature has exceptions as well as rules.

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Stages in the life of the mushroom; photo by Justin Pierce, CC BY-SA 3.0 license

Anyone who suspects that they have eaten a poisonous mushroom should visit a doctor for a diagnosis, treatment, information, and prognosis. The information below is intended for general interest.

The main toxins in death cap mushrooms are known as amatoxins. Alpha-amantin or α-amantin is the most dangerous type. It inhibits protein synthesis, which is a vital activity in our cells, and can cause serious liver and kidney damage. Someone who has been poisoned by the chemicals may require a liver transplant in order to survive. Amatoxins can’t be destroyed by cooking, drying, or freezing the mushroom.

According to the BC Medical Journal, the first gastrointestinal symptoms from the poisoning begin around six hours after mushroom ingestion. Twenty-four to seventy-two hours after ingestion, the patient experiences a false recovery phase. Although gastrointestinal problems weaken, the mushroom toxins continue to harm the body. The last stage is called the hepatorenal phase. This phase involves organ damage and may be very serious.

Medical procedures that may help a patient exist, enabling some people to recover from the poisoning. Though there is officially no antidote for the harmful chemicals, n-acetylcysteine and silibinin at a suitable concentration and administered in the correct form are said to have been helpful in some cases. Silibinin is obtained from the milk thistle plant. It’s important that anyone who may have eaten a death cap mushroom begins medical treatment quickly.

California is also experiencing a surge in Amanita phalloides mushrooms. The mushroom attracts dogs as well as people in the state. It’s just as deadly for our canine friends as it is for us. The fungus is spreading in other parts of the Pacific Northwest region of North America as well.

Some people enjoy foraging for their own food. The activity can sometimes be a risky business, especially when mushrooms are involved. Children should be taught that they must never pick a mushroom to eat. Other people should be extremely cautious if they decide to pick mushrooms. It’s a potentially dangerous activity.

References

Nature Discoveries: A Walk Along an Urban Trail in Burnaby

I live in a suburban area near a small, forested mountain. The mountain is a wonderful place to explore when I feel up to a climb, but at other times I’m happy to observe nature along the urban trail in my neighbourhood. Despite its name, the trail travels through treed and residential areas as well as urban ones. It’s bordered by cultivated and/or wild vegetation, depending on its location. There are always interesting things to see along the trail for someone interested in nature.

In this post I describe some discoveries that I made during a late February walk along a section of a trail. My journey began at the location shown in the photo below. I didn’t have to travel far in order to make some interesting observations.

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A section of the trail on the day after snow fell

There are other trails in Burnaby besides the one that I explored. Some of them connect to those in Vancouver, which adjoins Burnaby. A map of the trails and further information can be found at the City of Burnaby website. Information about the Vancouver trails—which are known as greenways—is available at the City of Vancouver website.

The urban trails and greenways are open to cyclists as well as pedestrians. The network provides the opportunity for people to explore many places and to travel for a long distance along a pleasant route. It also provides a safer trip for cyclists than a road with vehicular traffic would do.

We don’t get much snow in the Greater Vancouver area, but it’s occasionally possible to cross-country ski along a trail. The photograph below shows almost the same section of the trail as the photo above as it looked earlier on this February.

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Attractive tree trunks beside a snow-covered walking trail

Soon after I started my walk I saw the black cottonwood trees shown in the photo below. This wasn’t unexpected, since they are common trees beside the trail in my neighbourhood. Black cottonwood has the scientific name Populus balsamifera ssp. trichocarpa. The tree has a tall and straight trunk. The trunk is grey and develops noticeable grooves when it’s mature, as can be seen in the front tree in the photo.

The cottonwood tree is known for its seeds, which are covered by white hairs that look like cotton and give the seed a fluffy appearance. The hairs enable the seeds to be transported long distances by wind. Some parts of the trail are covered by fluff when the seeds are released from the fruit.

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Black cottonwood trees seen near the start of my walk

I was very pleased to see the first snowdrops of the year soon after I photographed the cottonwood trees. I’ve been looking out for the flowers and was happy to finally find some in bloom. They belong to the genus Galanthus.

Snowdrop flowers are delicate and drooping. They have two layers of petals. The outer ones are white in colour, which matches the snow that sometimes covers the plant’s base. The inner petals are white with green markings. The narrow leaves are also green. The plant grows from a bulb and is a perennial. These are useful features for someone who knows where the plants grow and looks out for them each year.

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Snowdrops

Douglas fir is another common tree beside the trail. It’s not a true fir, despite its common name. Some people like to hyphenate the term Douglas-fir to emphasize this fact. The plant’s scientific name is Pseudotsuga menziesii. True firs belong to the genus Abies.

The tree is named after David Douglas, a Scottish botanist who explored North America and collected plants. The species name is derived from the last name of Archibald Menzies, another Scottish botanist who was also a surgeon. Like Douglas, he explored North America and took some of its plant back to Britain.

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A Douglas fir cone

The cones of Douglas fir are easily identified due to the three-pronged flaps above each segment of the cone. An interesting legend says that they show the legs and tail of a mouse that is hiding in the cone. The middle extension of a flap is usually longer than the one on either side, unless it’s been broken off, so it’s quite easy to imagine that it’s part of a mouse. The needles of the tree encircle the branches, which helps to distinguish Douglas fir from some other conifers in the area.

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The canopy of Douglas fir as viewed from underneath the tree

I accidentally found my first dandelion of the year when I was looking at some moss. The flower was on a short stem and located very close to the ground, unlike the ones that develop later in the year. The bright yellow colour was lovely to see against the somewhat dreary background. The scientific name of common dandelions is Taraxicum officinale.

Though some people consider dandelions to be a nuisance, I like them. I’ve bought the leaves as a salad green from farmers markets. The young leaves are not only edible but taste good, too. Older leaves may taste bitter, however. People should be cautious if they want to harvest the plants from the wild. Dandelions can become contaminated by pollution, dirt, and pesticides. In addition, it’s vital to be positive about the identity of a wild plant before eating it.

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A dandelion close to the ground

I can’t say that the plant below is the first daisy of the year because a few are in bloom even in winter where I live. The prime time for daisies is spring and summer, however. This was the only one that I found on this particular walk. It should have a companion soon when the bud beside it opens up.

Bellis perennis (the English or common daisy) is indeed common where I live. The name of the plant is based on the old English term “day’s eye”. The yellow centre and the rays that surround it do seem somewhat reminiscent of the sun.

As in dandelions, the flower head or inflorescence of a daisy is a composite structure consisting central disk flowers (or disk florets) surrounded by ray flowers. In the case of daisies, the ray flowers are white. Both species belong to the family Asteraceae, which was once known as the Compositae.

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English daisy

When I was just about to leave the trail to buy some groceries, I found the gems shown below. (The trails travel to and by useful sites, such as shopping centres, schools, and parks.)  I loved the vibrant colour of the flowers compared to their surroundings.

Crocuses are common garden escapees that bloom beside the trail in late winter and early spring in my area. I never tire of seeing them. They belong to the genus Crocus and have a variety of colours. The most common colour that I see outside of gardens is the one shown in the photo below. For me, crocuses are one of the surest signs that spring is on the way.

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Crocuses

I’m looking forward to seeing new plants and animals beside the trail as the year progresses. The trail never looks quite the same for someone who observes the interesting organisms that border it. I often walk along the path and am always glad to do so.