A truffle or a sclerotium (mv. sclerotia), is an underground hardening or thickening of the mycelium, which are formed during periods of bad climatic conditions, in order for the organism to be able to survive this period. Thus, it functions as a parking place for moisture and nutrients, in order to enable the plant to form mycelium back later for vegetative and regenerative growth.
Technically and scientifically speaking, truffles are thus not mushrooms, and for this reason, they do not fall within the reach of the Opium Act. Truffles can be freely produced, purchased, sold and consumed.