Magic!

No, these are not the kind of mushrooms that make you "see things", but it is somewhat magical that the weather is moist enough in August for mushrooms to grow.
In fact, mushrooms are somewhat of a rarity here.

P.S. A little research indicated that these are: Chlorophyllum molybdites, the poisonous mushroom most frequently eaten in North America.The symptoms are predominantly gastrointestinal in nature, with vomiting, diarrhea and colic, often severe, occurring 1–3 hours after consumption.
Although these poisonings can be severe, none has yet resulted in death.