is this also a fungus?
Yes
Marasmius oreades
Marasmius oreades, also known as the fairy ring mushroom or fairy ring champignon, is a mushroom native to North America and Europe.
what is the marasmius rotula? A common species of agaric fungus does it have any uses? Yes, to bioaccumulate cadmium; and as a biocatalyst. which species are similar to this? Marasmius oreades
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Marasmius oreades [SEP] Introduction
Marasmius oreades, also known as the fairy ring mushroom or fairy ring champignon, is a mushroom native to North America and Europe. Its common names can cause some confusion, as many other mushrooms grow in fairy rings, such as the edible "Agaricus campestris" and the poisonous "Chlorophyllum molybdites".