Page 27 of The Exorcism of Faeries

Mycelium : the vegetative structure of fungi, comprised of hyphae—— tiny branching cells.

Microscopic threads called mycelium, in nature, create an underground communication network with other plants, exchanging nutrients, water, and even warning signals with each other. This same principle is at work within the specimens infected by the Irish Plague. The original spore manifests in the heart or lungs, sprouting into a mushroom, then uses mycelium to command the growth of flora throughout the body.

-Excerpt from The of Ariatne Morrow , circa 1993