B+.

What's known

Here's what's meant to be true and not.

What we actually know

• It has been in circulation since the late 1990s and is one of the most widely shared cubensis strains on earth.
• Genetically it is a plain Psilocybe cubensis. Not a hybrid, not a separate species.
• It throws big fruitbodies and drops a heavy, dependable purple-black spore print. That's why collectors love it.
• Independent lab testing puts its strength right around average for the species. As the saying goes, a cube is a cube.

What the community says

• It was released by an anonymous Florida hobbyist remembered only as "Mr. G".
• The name might mean "big-plus", might be a B-positive blood-type pun, or might just be an old distributor's grade. Nobody is sure.
• It was once sold as a cubensis crossed with Psilocybe azurescens. It isn't, and it can't be.
• It was once billed as the strongest cube going. It never was.

Where it came from

Every famous cube has an origin myth, and B+'s is one of the best because so much of it falls apart the moment you pull on it. As far as anyone can tell, the trail starts in Florida in the late 1990s with a hobbyist remembered only as Mr. G, who is said to have handed out spore prints to the early online mushroom scene and watched his strain spread through the spore vendors of the day.

Mr. G reportedly claimed he had created B+ through some heat-treatment experiment, then admitted he could never repeat it. Others of the era were said to dismiss the story as fiction. Then, like a good folk hero, he apparently vanished from the forums, and the strain he named outlived him to become one of the most-studied cubensis strains anywhere. Take all of it as hearsay rather than fact.

The answer to "what does B+ stand for?" is that nobody actually knows. Big-plus, B-positive, or a distributor's grade. The mystery is half the charm.

What to expect at the scope

The most stubborn B+ myth is that it's a cross between Psilocybe cubensis and Psilocybe azurescens, a rumour fed by the slightly pointed caps B+ sometimes throws. It's a great story with a clean ending: the two are wildly different mushrooms. Cubensis is a warm-climate dung-lover; azurescens is a cold-coast wood-rotter. No such cross has ever been validated, and the people who chased it down all reached the same conclusion. B+ is just a very good cubensis.