one of several specialized forms of a mycelium (a) mycelial fan: a fan-shaped mass of hyphae formed between bark layers or between the bark and wood of trees, (b) mycelial felt, plaque, plate, or fungal mat: the hyphae aggregate into dense, compact masses resembling felt cloth or paper, occupy cracks or cavities in the host tissue, are usually thicker than mycelial fans, and are common in Fomes laricis, (c) mycelial cord or strand: an aggregation of mycelia into filamentous strands, (d) rhizomorph: an aggregation of mycelia into cordlike or tapelike strands with a melanized outer layer and a specialized cortex, e.g., Armillaria root disease, (e) sclerotium: a densely compacted mass of hyphae varying in size from minute to several inches in diameterThis definition last updated 07/20/2008