Rhizomorphs are thread-like or cord-like structures found in fungi, made up of parallel hyphae and branched tubular filaments that comprise the body of a typical fungus. They act as an underground absorption and growth system that invades and decays roots and wood, and can reach areas where food resources are scarce. Rhizomorphs can help fungi to spread and colonize new areas. They can appear as a hyphal strand aggregation that looks like a rope, and derive their name from their resemblance to plant roots. Rhizomorphs can be found in the ground, under the bark of dying trees, or wrapped around decaying stumps. They can be plant allies, plant enemies, or neutral decomposers, depending on the fungal species causing them and the health of nearby plants.