Auricularia Auricula-judae - Habitat, Ecology and Distribution

Habitat, Ecology and Distribution

Auricularia auricula-judae grows upon the wood of deciduous trees and shrubs, favouring elder. In up to 90% of cases, the mushroom is found on elder, but it is often incorrectly assumed to grow exclusively on elder. It has also been recorded on Acer pseudoplatanus (known in the United Kingdom as sycamore), beech, ash, spindle, and in one particular case, the sycamore draining board of an old sink in Hatton Garden. In Australia, it is found in Eucalyptus woodland and rainforests; in the rainforests, it can grow in very large colonies on fallen logs. It favours older branches, where it feeds as a saprophyte (on dead wood) or a weak parasite (on living wood), and it causes white rot.

Commonly growing solitarily, it can also be gregarious (in a group) or caespitose (in a tuft). Spores are ejected from the underside of the fruit bodies with as many as several hundred thousand an hour, and the high rate continues when the bodies have been significantly dried. Even when they have lost some 90% of their weight through dehydration, the bodies continue to release a small number of spores. It is found all year, but is most common in autumn. It is widespread throughout temperate and sub-tropical zones worldwide, and can be found across Europe, North America, Asia, Australia, South America and Africa. There has been some debate about the appearance of the species in the tropics; while it has been frequently reported there, Bernard Lowy, in an article on Auricularia, said that "of the specimens I have examined, none could be assigned here".