Panaeolus cinctulus, also known as panaeolus subbalteatus or the "Banded Mottlegill," is a mushroom that contains psilocybin, known for producing hallucinogenic or psychotropic effects. It grows throughout the United States and in most of North America. It has also been found on several additional continents, including Europe, Africa, and Australia.
Panaeolus cinctulus generally pop up after it rains. They tend to grow abundantly on compost piles and on well-fertilized lawns and gardens. Although they may be found near sites fertilized with horse manure, they will rarely grow in the manure itself. The cap of the mushroom is 1.5 to 5 inches wide and either flat or convex. It is a reddish-brown color when moist, but dries to a white or dull white shade.
Panaeolus mushrooms typically sprout when the humidity is at or near 100 degrees and the nutrition in the soil is good. Consequently, the first step to dealing with panaeolus cinctulus that has invaded a lawn or garden is to stop fertilizing the soil. Without a source of nutrients, panaeolus cinctulus will eventually use up the nutrients in the soil and die out. Since panaeolus cinctulus typically needs humid air and well-moistened soil to survive as well, withholding water until the mushrooms disappear may also speed their destruction, as long as it will not also damage the lawn or garden plants.
If panaeolus cinctulus sprout in an area covered with straw or mulch, remove the mulch by raking it carefully. Raking while the mulch or straw is still wet will help prevent the panaeolus cinctulus spores from spreading. In an urban or suburban area, dispose of the mulch or straw in tightly closed plastic lawn bags to prevent the spores from invading neighboring lawns or gardens. In a rural area, the infested mulch or straw may be taken far from cultivated areas and dumped with the permission of the property owner.