Mycelium

Mycelia, also known as mycelium, is a fungi's mass of branching, tubular filaments (hyphae). The thallus, or undifferentiated body, of a typical fungus, is composed of mycelium. It can either be tiny in size or grow into visible structures, such as brackets, mushrooms, puffballs, rhizomorphs (long strands of hyphae fused together), sclerotia (hard, compact masses), stinkhorns, toadstools, and truffles. It generates spores at a specific time, either directly or via unique fruiting forms.