Truffles are Sclerotia, a self defense mechanism for certain mushrooms. The morel includes sclerotal formation in it's fruiting and life cycle. the P. Cubensis grower who discovered the secret to growing morels accidentaly, it could have been me, it wasn't. In the instances of sclerotal formation in the p. variety, it is said that they grow up against what it "senses" are impenitrable barriers (like glass). It is also said that the sclerotia, even when completely dry can be revived. Now I believe it, but I have never managed to make it work. They are, when fresh, somewhat more potent than the fruit by weight because they are only 70 percent water. After they dry they are somewhat less potent and they do not seem to keep very well.