B+ is a strain of Psilocybe cubensis, a well-known hallucinogenic mushroom species[i]. The B+ strain is popular with growers because it is easy to work with, accepting a very wide range of growing conditions and substrates and producing large, thick caps. Though not the fastest-grower among P. cubensis strains, B+ is not the slowest, either. Color can vary a little, depending on growing conditions; enthusiasts describe the large golden to caramel-color caps as “beautiful.”
About Psilocybe cubensis
It can be difficult to learn much about P. cubensis[ii] besides its use as a “magic” mushroom, since many writers focus on that one point to the exclusion of all else. Yet even if a person’s primary interest is the “magic,” learning about the mushroom provides necessary context.
P.cubensis is one of a number of closely-related psychoactive species, though it is the most well-known (there are also other psychoactive mushrooms that are not closely related to P. cubensis and have somewhat different effects). The substances responsible for the psychoactive effects are psilocybin, psilocin, baeocystin, and norbaeocystin. The concentration of these substances can vary significantly from one individual mushroom to another.
Although P. cubensis is not generally considered toxic (but see note under Cautions!) it closely resembles a number of other species, including the aptly-named Deadly Galerina. Growing “magic mushrooms” at home is substantially safer than harvesting them wild, and multiple cultivated varieties, including B+, exist, often with creative, funny names.
Cap: Curved to flat on top, usually smooth. Variable in color, but generally light brown with a dark center. The interior flesh is white but bruises blue.
Gills: Initially gray, darkening to purple and then black, but usually with pale edges. Very young specimens still have a veil covering the gills.
Stem: Often very long. Whitish, but bruises blue. After the veil rips as the cap expands, veil remnants remain in a ring of tissue around the stem, like a skirt. Though the ring is actually white, once the purple spores are released some of them land on the ring and turn it purple.
Spore Color: Purple.
Habitat: In the wild, P. cubensis feeds on and fruits from cattle dung. It is distributed over much of the world, in part because it follows cattle; cattle egrets, birds that specialize in hunting insects near cattle, carry the spores to new pastures.