 The bulk of "Aureoboletus mirabilis" is typically hidden from sight, existing as masses of almost invisible fungal threads called mycelium, which form the active feeding and growing structures of the fungus.The mushrooms, or fruit bodies are created solely for the production of spores by which the fungus reproduces itself.The caps of the fruit bodies are up to in diameter, red or brownish-red in color, initially convex but flattening out as they develop.