Mindful Mycelium
B+
Identification: Psilocybe cubensis var “B+”
In the wild:
“B+” P. cubensis are a rigorous, fast-colonizing, and contamination-resistant mushroom. B+ is one of the more commonly known P. cubensis varieties.
B+ is considered to be one of—if not the most—versatile cubensis mushrooms. These mushrooms tend to grow less uniform, but with larger fruiting bodies. “B+” is extremely aggressive against contaminants when found in its natural environment. Each combination of genetics producing something different every time, with a high chance of variable appearance.
“B+” was initially discovered growing in Florida in extremely hot and humid environments.
Key Characteristics
Appearance: Known for producing large, caramel-to-golden brown caps that often feature a slightly darker center. The stems are typically thick and robust, sometimes bruising bluish when handled.
Resilience: B+ is famously forgiving. It is highly resistant to environmental stressors and contamination, making it a favorite for beginners studying mushroom growth and development.
Microscopic Features
Under the microscope, B+ spores display deep purplish-brown tones and smooth, ellipsoid shapes.
Potency
It is considered to have moderate-to-high potency compared to other Psilocybe cubensis strains, though potency can vary depending on growing
J Fungi (Basel). 2026 Apr 7;12(4):265.
Lore
The "Mr. G" Legend: The exact origins of the B+ strain are shrouded in mystery, but it is widely attributed to a Florida-based mycologist and breeder known simply as "Mr. G".
The 1990s Debut: Mr. G is believed to have developed and distributed the strain’s spore prints to early collectors and vendors in the mid-to-late 1990s.
The Name: According to widespread mycology forum lore, the "B" stands for "Big fruits" and the "+" represents "really big fruits," though some suggest the name simply implies an overall highly rated or "B-positive" specimen.
