The term "parasite" referring to animals, pokemon, plants, and diseases which live off the nutrients of a host is derived from the pokemon Paras. As most parasites are microscopic, or at the very least internal and much smaller than the host, it is commonly believed by children and the undereducated that the mushrooms on Paras' back soak up nutrients from the Paras.
In reality, the reverse is true; they are not called "mushroomites" after all. A Paras' mushrooms are not true mushrooms, but a plant which has evolved to look like a fungus to protect itself from predators. They can be found on their own in varying quantities, sometimes even in abundance, but there are no Paras without "mushrooms" on their back. Paras attach these plants to their backs, leeching chlorophyll from the Sun, as they are too slow and weak to find food on their own.
This relationship is not, however, a wholly one-sided affair. When planted on a Paras' back, mushrooms are known to grow larger and spread their seeds further than when left in the ground. In truth, the term "parasite" is a complete misnomer, albeit one which remains in the language through established use and the lack of an alternative.
