Long-lived and among the largest organisms in the world. Armillarias live on wood of live and decaying trees. There is an Armillaria ostoyae that is thousands of years old and takes up 3.4 square miles. At least 10 species in US under the name Armillaria mellea. Most species are saprobic, but a few are parasitic and cause ‘white rot.‘ The rhizomorphs of Armillaria are called ‘foxfire’ because they bioluminese in the dark. The can grow at the rate of about 3 metres annually. Most species are tolerated by most people, but some are sensitive to them - especially if the mushrooms are a bit over-the-hill. Those that grow on conifers seem to be less tolerated than those that grow on deciduous wood. 034-001