While Chaga is commonly referred to as a mushroom, the part of the Chaga that is wild harvested is actually not a mushroom but a sclerotium. A sclerotium is a hardened, dense mass of mycelium. Chaga is unique in that it is not pure mycelium like other sclerotia’s (poria, polyporus) as much of the mass is actually wood fiber which comes from the tree is grows on.
