Bluecap fungus was the main staple grain of the Underdark, where they absorbed magics of Faerzress. They were inedible in their raw state, but the fungi could be ground into a bland flour and baked into "sporebread". Bluecap was known for its ease of cultivation, and it was propagated by many sentient Underdark creatures. A loaf of sporebread was equivalent to one pound of other nutritious food.
The caps of bluecap mushrooms could be prepared by those with the correct herbalism knowledge to make a stew that would neutralize some minor poisons.