Mycelial cord

As well as growing underground or on the surface of trees and other plants, some fungi make mycelial cords which hang in the air from vegetation.

These root-like structures are composed of parallel-oriented hyphae that can be found in several species of wood-decay and ectomycorrhizal basidiomycete as well as ascomycete fungi.

[3] Rhizomorphs can facilitate the colonization of some dry-rot fungi such as Serpula lacrymans and Meruliporia incrassata and cause damage to homes in Europe and North America, respectively, by decaying wood.

[10] Rhizomorphs act as a system of underground absorption and growth structures that invade and decay roots and wood,[11] as well as sometimes propagating through the air.

One of the more common morphological characteristics for the genus is the presence of an annulus, which is a ring-like structure in the stem of the fruiting body with exception of the species Desarmillaria tabescens.

[12] In a controlled environment study with high levels of oxygen and saturated soil moisture content, Desarmillaria species produces melanized rhizomorphs[13] However, these two conditions are difficult to find in the climate of today and could explain the lack of melanized rhizomorphs in nature and could be a carryover from previous evolutionary periods.

Melanin in rhizomorphs are known for the absorption of metal ions from the soil and can be found in different structures such as spores and cell walls of fungi among others.

DNA analysis has shown it to belong in the Marasmiaceae (normally a mushroom-forming family), but no fruiting bodies or other fertile structures of it have been found.