Mycelium

Mycelium isvegetative part offungus consisting ofmassbranching threadlike hyphae that exists belowground or within another substrate. Itthroughmycelium thatfungus absorbs nutrients from its environment. Myceliumalsovital componentmany ecosystemsthathelps increaseefficiencywaternutrient absorptionmany plantsalsovital todecompositionbreaking-upplant materialformorganic partsoil andrelease carbon dioxide back intoatmosphere.

The mycelium ofHoney mushroom, Armillaria bulbosa (= A. gallica),its clones has been estimatedextend over 15 ha (37 ac) withprotoplasmic mass10,000 kg (22,000 lb)an age1500 years (Smith et al., 1997). At this sizeage, A. gallica islargestoldest livingonplanet.

The familiar hat-like headstalkmushroomsin fact reproductive structuresascomycetesbasidiomycetes fungi, andnot classified as mycelium.

• See also: mycorrhiza, carbon cycle

Reference

• Smith , M., Bruhn, J.,Anderson, J. 1992. The fungus Armillaria bulbosaamonglargestoldest living organisms. Nature 356:428-431.