Mushrooms are fascinating creatures. Did you know, that the mushrooms we see in the forest are actually just a tiny part of the mushroom itself? Mushrooms live in the ground as a thread called mycelia, some in symbiosis with trees. The mushrooms that appear on the ground are mushroom’s means to spread spores in order to disperse into the surrounding nature. The biggest known mushroom is Armillaria solipides, and it covers 8,8 square kilometers which equals to 1665 football fields! It’s estimated to be 2400 years old, so it has had plenty of time to grow below ground in Oregon, US.
The mushrooms that appear above the ground have fairly short life cycle. Especially with Boletus species (Tatti) the harvest time is only few days. Let’s use Amanita fulva (Ruostekärpässieni) as an example to illustrate the growth of a mushroom. Amanita fulva belongs to the Amanita species. Finland has 24 known Amanitas, some are deadly poisonous and some are eatable. Probably the most known Amanita is the poisonous Amanita muscaria (Punakärpässieni), with its bright red cap with white warts (remainings of the univesal veil). Amanita fulva is one of the eatable Amanitas. I do not recommend you to pick and eat any of the Amanitas unless you have been trained to identify them, as the risk of mistaking it with any of the poisonous Amanitas may be a deadly mistake. Even the eatable Amanitas need to be properly prepared to remove the poisonous effect. I’m using Amanita as an example of the growth only because of its beautiful and quickly evolving shape.
Growth of Amanita fulva
Amanitas have a shield – also called as universal veil- that makes them look like tiny eggs when they appear from the ground. The shield breaks as the mushroom grows, and part of it stays as a cup (or a volva) in the base of the stem. Here you can see only the cap and cup. For a beginner the rule of thumb is that if a mushroom as a cup (volva), leave it to the forest!
When mushroom grows, it changes its shape again. The cap starts to change its shape and also the stem appears from the cup. Cap is a cylindrical or bell-shaped when mushroom is young.
When mushroom grows more, the cap starts to change its shape. For this particular Amanita, the cap is first closed bell-shaped and then it opens up convex. When it is fully grown, the distinctive character appears: the comb shaped striate edge of the cap is easy to recognize. The Finnish name Ruostekärpässieni refers to the rust color of the cap.
Finally, Amanita starts to decay. Even with the decomposed mushroom the comb shaped edge of cap is recognizable.
As you can see from the pictures, it’s important to learn the anatomy of the mushroom and be able to recognize how it looks like during its different life cycle phases. Young mushroom may have different lookalikes than the older ones.