Description B Cubensis Mushroom Spore Syringe Description: B Cubensis Mushroom Spore Syringe. The B Cubensis Mushroom is a very-easy-to-cultivate and a fast-growing strain. Ideal growing circumstances are best for B Mushrooms really large mushrooms, especially a substrate that is rich of nutrients. A really big caramel-colored cap will be formed then. But, these mushrooms will also grow quite well under mediocre conditions. Included with each syringe purchase: One 10cc mushroom spore syringe filled with B Spores. One sterile 16 gauge needle per syringe purchased and an alcohol prep pad.