Life

The mycelium

Yeast and some fungi are unicellular organisms, but most species are multi-cellular organisms, composed of masses of filaments known as hyphae, which altogether compose the mycelium or body of the fungus. This structure differs according to the function that the organism has to serve. Saprobic fungi have special hyphae, called rhizoids, which anchor the mycelium to the substrate, while some parasitic fungi develop hyphae, called haustoria, which invade the cells of the host organism. The hyphae in a mycelium grow very quickly, even more than one kilometre a day. The mycelium can be found in different forms: in single and scattered hyphae or as a fluffy mass, sometimes in very complex forms as in the case of edible mushrooms (boletus edulis, field mushroom, honey mushroom). They have a structure composed of a stipe and a cap which surfaces above ground level, while the part accommodating the reproductive structure of the fungus is underground (you will find various examples of the structure of mushrooms on the photo album).