Although mildly psychoactive, Calamus is not a hallucinogen, and does not produce effects similar to LSD. It's reputation as a psychedelic is based on a page or two in a book called 'The Hallucinogens' by Hoffer and Osmund.
Virtually all that you hear quoted and misquoted comes from these two pages. Hoffer and Osmund wrote about people who told them about how they used it twice. I find the information presented misleading and overstated.
Furthermore, this false reputation has lead to people unfamiliar with this medicine looking for a legal 'high', only to spend hours with agonizing nausea, stomach cramps, and extreme vomiting.