Agaricus Melleus Small 115×320 Medium 230×640 Large 368×1024 Download Tiff Original 863×2400 | (344.0 KB) Description Shown is a pine root attacked by the mycelium of agaricus melleus. The mycelium is in the form of rhizomorpha fragilis. Keywords Agaricus, agaricus melleus, mushroom, mycelium, rhizomorpha fragilis Galleries Mushrooms Source: Nicholson, George The Illustrated Dictionary of Gardening, Div. VI (London, England: L. Upcott Gill, 1884)