The B+ magic mushroom is a Psilocybe cubensis, a species of psychedelic mushroom. It’s main active elements are psilocybin and psilocin. The p. cubensis species is the most known psilocybin mushroom. Their status is established because p. cubensis are widely distributed and very easy to cultivate.B+ Magic Mushrooms The B+ is a domesticated hybrid mushroom of unknown origin. Under a microscope, this strain closely resembles a P.cubensis but shares some characteristics resembling a P.azurescens. It’s a unique P.cubensis strain and performs very well indoors making it a popular strain for home hobbyists.