Nature provides some beautiful plants that offer sustenance, visual delight, and sometimes hallucinations. Many plants that now adorn lawns and gardens were once parts of religious ceremonies. The flowers that can cause hallucinations often come with a price--death. Be careful when you select plants, especially if you have pets or children.
Listen for the trumpet of angels if you consume the flower of the plant, Angels Trumpet, or Brugmansia. These highly toxic plants were once part of the religious ceremonies of the Taino Indians of Puerto Rico. The tea from the plant, called campinella in some circles, produces a horrible hallucination. Some feel that it is the worse that they have ever experienced. It also is deadly and may cause brain damage that changes the user's ability to differentiate reality from fantasy.
Watch out for Jimson weed. The name came from the wild plants that grew around Jamestown. You sometimes hear the name in cowboy movies, when cattle and sheep die. There are often cases of this occurring if the animals ingest the plant. Sometimes even smelling the plant causes a headache. Although folk medicine practitioners use the plant medicinally, too much of the plant, causes dilated pupils, thirst, fever, confusion, labored respiration, convulsions, coma and hallucinations.
Question anything called Angel Trumpet. Datura inoxia is another plant, which is hallucinogenic and also called Angel's Trumpet. The related horn-of-plenty (Datura metel) is also toxic and causes hallucinations. These plants sprawl, unlike the Brugmansia that is woody. The Native Americans of the North American Southwest used them in religious ceremonies. They cause hallucinations, but are not as toxic as the Brugmansia.
Monkshood or wolfbane traces some of its hallucinogenic properties to a mixture with belladonna. Witches often used the two in combination as a lotion to rub on themselves. The mixture caused hallucinations and stories say that it allowed the witches to fly. Chances are, their spirit flew because the concoction is toxic, or they simply hallucinated flying. Monkshood numbs the area it touches and causes the heart to slow.
Use nightshade, or belladonna, and you will trip yourself to death. The name belladonna comes from its original use, as a beauty product. Drops made from the plant put into the eyes of Italian women dilated the pupils. Hence, the plant received the name belladonna meaning beautiful lady. The flowers are bell shaped and purple with hints of green throughout. They grow on a sub shrub root-stock.
Papaver somniferous is the opium poppy. While growing the plants is illegal in the United States, you often find seed packets for it available. The name is Latin for "to eat" and "sleep inducing." Pap was food given to children. It was common practice in early Rome for parents to give children some of the juice from the pod of the plant to make them sleep. This often sent many to a much longer sleep than the parents intended--an early grave. Other poppies that bring hallucinations are the California poppies.