The black witches’ butter (Exidia glandulosa) is a jelly fungus, so from former group of heterobasidiomycetes, close to the most popular Jew’s ear (Auricularia auricula-judae). It develops black, shiny, lobular pads, 5-15 mm thick, on fallen woods mainly from oak and beech. In wet weather it swells as a blister with shiny black surface plenty of small, less than 1 mm papillae. However, in dry weather it shrinks to a fragile layer. The black witches’ butter causes white spoilt of the wood.
The black witches’ butter is seen from end of autumn to beginning of winter.
[photo Jordi Badia]