According to this, “the feeding fronds on a type of slime mold” have memristance. In living organisms the only other places memristance has been found until now are in “human sweat glands, blood and some tree leaves”.
Memristance … is where a material has the … property of undergoing a change in electrical resistance as current is applied. When applied in one direction, resistance increases; when applied in the other, it decreases. More importantly perhaps, such materials also have the remarkable ability to “remember” how much resistance was being applied when the power was turned off. When electricity is restored, the material has the same resistance it had at its prior stopping point.