Today we are going to talk about a species of fungus that has both positive aspects because it can become edible with caution but has negative consequences because it causes a disease in the trees that it invades. It’s about the Armillaria mellea. This fungus grows at the base of the trunks of certain tree species and infects them with a disease.
In this article we are going to show you the characteristics, problems it causes and edibility of the Armillaria mellea.
We are going to describe the parts of the fungus to get to know its characteristics and how to identify it with the naked eye. If we see his hat, we can see that it reaches about 15 cm in its maximum splendor. May be convex, flattened, or wavy in shape. Normally, you can know how old the fungus is, because when it is already developed and its old age begins, you can see the mameloned hat. The color is similar to honey, although it has yellowish tones. It is covered with small brown scales that tend to disappear because of the rain.
The plates that it has are a little decurrent. They are lighter in color when the mushroom is young. As they mature and develop, they are filled with yellowish spots that later turn brown or reddish in their old age.
As for the foot, it is generally quite long, curved and spindle-shaped. Its color is yellowish ocher and it turns brown over time. We can see a fairly wide ring with a yellowish membranous appearance on the foot.
Its meat is firm in the hat and white in color. However, when we get closer to the foot, we see how the meat changes its structure and texture to something more woody and fibrous. The flavor of this mushroom is mild in young specimens. It is not edible in adulthood, since they tend to have a bitter and more unpleasant taste with a fairly strong smell.
They are mushrooms that can be found from September to early winter. At this time is when they develop with the first rains of autumn. The problem is when it grows tussock on some tree stumps. They can be seen in groups of numerous individuals.
It is eatable?
There is no culinary tradition that makes you eat Armillaria mellea. In some European countries there are. It is true that the hats of the youngest specimens Yes, they can be tasted if they are previously boiled.. Being a parasitic species, it causes irreparable damage to trees. This causes the species to end up acting like a saprophyte.
It is a mushroom that is easily confused with Armillaria ostoyaewhich has a more brownish color and a white ring. To be able to eat these mushrooms, it must be an individual that is not in an adult phase and that they are previously boiled. These conditions make their treatment, transport, storage, etc. Be something more complicated. As it is not in high demand in the culinary field, there are areas where they are growing abundantly. This is a problem for the trees you are parasitizing as we will see below.
Disease Armillaria mellea
This fungus produces in the trees that parasitize what is known as white rot. It is a root mycosis that forms white rots throughout the root system of trees. It also attacks the root neck of numerous tree species such as oaks, beech, birch, pines, holm oaks and poplars. These fungi predominate in soils with a silty-clay texture and more compact. By having a compact soil, the drainage is quite bad. For this reason, puddles easily occur that accumulate moisture and suffocate the roots.
The spread of the disease increases when the distribution of these fungi is palisade. Being some specimens of trees close to each other, it is easier for them to be infected. In the lands where you see that they are affected, it is better not to cultivate species like the ones we have named for at least a 10-year period. Otherwise, they will be infected as soon as they grow a little older.
We are going to describe the damages and symptoms that we find in the species that are affected. The symptoms that we see on the roots are easily recognizable. At first, you can see that it is from a browning and blackening of the rind. When it is in this state it is already possible to detect with the naked eye that it is infected. As the parasites develop along the root system, the first tissues are attacked from the bark and disintegrate, transforming into a kind of fibrous mass. This mass can be recognized by a color that ranges from brown to black, depending on the species.
If the infection reaches the roots closest to the neck, may progress upward toward the base of the trunk. It is then when you can see a lesion at the foot of the same and that will manifest itself in the form of exudations of sap or gum. This is how you identify a tree that is infected with rot caused by Armillaria mellea.
On the aerial parts of the plant, the fungus produces symptoms that are not at all typical in rot fungi. This is because the root system is disturbed first.
Control of Armillaria mellea
We have talked about the symptoms and how to recognize the disease. Now it is time to move on to how this disease is controlled so that it does not affect the trees. Most of the methods to date that are effective are prevention. Once the fungi are established in the roots of the plant, it is very difficult to save it. If some trees are to be planted on contaminated land, all pre-existing stumps and roots on the land must be removed and destroyed. It should be watered with SO4FE with a 10% solution in those areas where the roots cannot be extracted. Afterwards, the land must be tilled and crumbled well and aerated.
Whenever possible, it is advisable to install the plantation on a plot that has had herbaceous crops for several years. This is where fungi are least likely to attack.
I hope that with this information you can learn more about the fungus Armillaria mellea.