Apparently seeking a psychedelic high, two teenagers ended up violently ill and hospitalized in critical condition Sunday night after eating flowers from a poisonous angel's trumpet plant growing in People's Park.

The two 17-year-old boys, whose names were not released, have since been upgraded to good condition at Alta Bates Medical Center in Berkeley, UC Berkeley spokeswoman Marie Felde said Wednesday. A 16-year-old girl who had a less violent reaction was treated and released.

"It sounds like they will all be OK, but it's a good idea to let people know not to eat these plants," Felde said.

UC owns and manages People's Park. The teenagers were staying in UC dormitories for an independent summer program for high school students through Education Unlimited in Berkeley, Felde said.

"It's fair to say these kids had a miserable experience," said Matthew Fraser of Education Unlimited. "I don't think they'll be doing it again."

About 11:30 p.m. Sunday, university police got a call from the dorms saying someone had eaten a toxic flower and was having a bad reaction. The boy was taken to Alta Bates. The second boy and the girl went to the hospital on their own.

Angel's trumpet -- nicknamed devil's weed -- is a common and popular flowering shrub native to South America and related to the jimsonweed. With its dangling, funnel-shaped, peachy-white or purple flowers, it is sold in nurseries for decorative gardening and can be found popping up on its own all over the United States, blooming mainly in summer and fall.

It has long been known for producing hallucinogenic thrills -- but at a price.

All parts of it are poisonous, especially the leaves and seeds inside the flower, said Dr. Kent Olson of the California Poison Control System in San Francisco.

The alkaloid toxins from even just a small amount can produce headache, thirst, nausea, hypertension, heart arrhythmia, severe agitation, fever, blurred vision, hallucinations, delirium, heat stroke and even coma.

"We get about 20 calls a year about this kind of plant," Olson said. "It's very potent. Because of the symptoms, patients suffering from this are often referred to as blind as a bat, dry as a bone, hot as a hare and mad as a hatter.

"It's not usually life-threatening, but produces extreme reactions," he said. "One of the most uncomfortable problems is it blocks the ability to urinate. People often come to the ER screaming in pain because of that aspect.

"That's a pretty nasty side effect for getting high," he said.

The teenagers apparently ingested the brugmansia versicolor variety of the plant, which can grow up to 15 feet tall with 15-inch-long peachy white blooms.

The People's Park plant has since been removed by park gardeners "just to be safe," Felde said. "We've never had a problem like this before, and we don't want anyone trying it again."

"Everybody's known about (angel's trumpet) for years," said one People's Park regular. "Back in 1968, I remember people talking about it, but the effects didn't seem very desirable to me."