What is "sclerotium"

Sclerotium \Scle*ro"ti*um\, n.; pl. Sclerotia. [NL., fr. Gr. sklhro`s hard.]

1. (Bot.) A hardened body formed by certain fungi, as by the Claviceps purpurea, which produces ergot.

2. (Zo["o]l.) The mature or resting stage of a plasmodium.

n. A compact mass of hardened mycelium stored with reserve food material that, in some higher fungus such as ergot, becomes detached and remains dormant until a favourable opportunity for growth occurs.

A sclerotium , plural sclerotia , is a compact mass of hardened fungal mycelium containing food reserves. One role of sclerotia is to survive environmental extremes. In some higher fungi such as ergot, sclerotia become detached and remain dormant until favorable growth conditions return. Sclerotia initially were mistaken for individual organisms and described as separate species until Louis René Tulasne proved in 1853 that sclerotia are only a stage in the life cycle of some fungi. Further investigation showed that this stage appears in many fungi belonging to many diverse groups. Sclerotia are important in the understanding of the life cycle and reproduction of fungi, as a food source, as medicine (for example, ergotamine), and in agricultural blight management.

Examples of fungi that form sclerotia are ergot ( Claviceps purpurea), Polyporus tuberaster, Psilocybe mexicana, Sclerotium delphinii and many species in Sclerotiniaceae. The plasmodium of slime molds can form sclerotia in adverse environmental conditions.