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You can also study these spores and the lamellas using a button mushroom or
another culinary mushroom. For this, pluck the lamella of a mushroom that is
as young as possible and place it under the microscope. Or try to make a thin
cross-section of the cap of a young button mushroom. What you will see there
is explained below using the example of another fungus along with micro-
scopic photographs.
spore
Basidium cells form
the fruit layer
Central cavity made
of fungal hyphae
A Fungus Introduces Itself
The photos to the right show a thin cross-section through the cap of an inky
cap mushroom (Coprinus), which is commonly found in forests and gardens.
For the pictures, an entire cap from a young and very small mushroom was cut
crosswise through the stem and crosswise through the lamellas. And what can
you see in the pictures?
In the middle of the images, you can make out the cut fungal threads which
extend from the ground in the stem upwards and finally form the cap. Starting
from this central point the lamellas extend outward. At lower magnification,
the lamellas look as if they were surrounded by a black fringe. At higher mag-
nification, you can finally see that these are actually vast numbers of small,
dark dots, the fungal spores. While the spores are still ripening, the lamellas
are closed. Only when they are ripe do they open up, and the spores are then
released freely. You can also see very similar structures under the microscope
yourself, for example in a button mushroom.
Friend and Enemy
Many fungi are a true enemy of plants and animals, because they grow where
they shouldn't: on living organisms. In some cases, they can cause great harm to
the organism on which they grow as a pathogen. For us humans, fungal diseases
are normally not very dangerous. As long as our body is healthy and in good con-
dition, it is able to successfully defend itself against the establishment of fungi. If
a fungus, such as a foot fungus, does take hold, it is generally a nuisance but not a
hazard.
This is not the case with plants. The majority of all plant diseases are fungal diseas-
es. If a plant is damaged somewhere, for example because an animal has nibbled
on it, then fungal spores — which constantly surround us in great numbers — can
penetrate into the plant, germinate, and wreak lots of havoc.
But fungi are not fundamentally plants' enemies. There are also fungus-plant part-
ners that cannot survive without each other. This is referred to as symbiosis. One
example of this can be found in lichens.
cap
stem
lamella
Lamella with spores
Top view of the cap cross-section
Point at which the lamella is attached to the stem
The fungus known as pear rust is a plant disease
and causes these rust-brown spots.
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