The PES in PES Mushrooms comes from Pacifica Exotica Spora
The name of the company that first offered the spores of this psychoactive mushroom (reportedly first found in the Amazon) for sale. Now, PES Amazonia is widely available.

PES Amazonia is yet another cultivated strain of Psilocybe cubensis, the best-known of the “magic” mushrooms, the one most people mean when they refer to “shrooms.” It’s not the only source of “magic,” there are many other species that contain the same active ingredient, psilocybin, plus some species, such as some of the Amanitas, that contain other psychoactive substances. P. cubensis may owe its popularity to the fact that it’s intermediate in potency, neither too weak nor too strong, and easy to grow. In the wild, it feeds on the dung of large animals, but it’s usually cultivated on grain.

The different strains do seem to vary in their potency. Whether they also vary in their effects—whether equivalent doses would provide different trips—is debatable. Some people insist that psilocybin is psilocybin, and that therefore a cube is a cube. Others are sure there’s a difference. It might seem like the question would be easy to resolve, but it’s not, because trip experiences vary so much. The user’s personal biochemistry, mindset, and even current circumstance can all have a huge impact on how the experience goes.

That being said, PES Amazonian is said to be a potent and very spiritual strain. These mushrooms are typically very large. The caps are reddish, especially when young.

Effects
Generally speaking, psilocybin causes euphoria or other changes in mood, changes in thought-pattern often including spiritual or personal insight, and, at higher doses, hallucinations. Less-enjoyable effects commonly include excessive yawning, nausea, and sometimes vomiting. Severe reactions, such as convulsions, are very rare, but can occur. Psilocybin is relatively safe, but it is not risk-free.

Among the most common negative effects is anxiety, which can become extreme—despite the fact that psilocybin has also been advocated as a treatment for anxiety and depression. Some people say that psilocybin is an enhancer, exaggerating whatever mindset the user is already in.

PES Amazonian[ii] specifically is said to be less visual and more mental or spiritual than many of the other strains. The high can last up to eight hours.