text: peniophora quercina peniophora quercina is a species of wood - decay fungus in the family . the species produces fruit bodies which vary in appearance depending on whether they are wet or dry . the wet fruit bodies are waxy and lilac , and attached strongly to the wood . when dry , the edges curl up and reveal the dark underside , while the surface becomes crusty and pink . p. quercina is the type species of peniophora , and was moved to the genus upon its creation by mordecai cubitt cooke . the species is found primarily in europe , where it can be encountered all year . though primarily growing upon dead wood , especially oak , it is also capable of growing upon still - living wood . taxonomy early descriptions of the species came from carl ludwig willdenow , who named it lichen carneus in 1787 , and jean baptiste françois pierre bulliard , who , in 1790 , named it auricularia . however , the sanctioned name is thelephora quercina , given by christiaan hendrik persoon in 1801 , and sanctioned by elias magnus fries in the first volume of his systema mycologicum . the specific name quercina is in reference to quercus , the generic name for oak . a number of authors ( including jean - baptiste lamarck , lucien quélet and giacomo bresadola ) reclassified bulliard 's auricularia throughout the 19th century , while persoon 's thelephora quercina was reclassified by samuel frederick gray in 1821 , who placed it in as . however , in 1879 , mordecai cubitt cooke transferred the species to his newly described genus peniophora , declaring it the type species . despite subsequent attempts at reclassification , cooke 's name is the one currently used . description peniophora quercina produces resupinate fruit bodies which vary in appearance depending on whether they are wet or dry . they are up to 0 . 5 mm ( 0 . 020 in ) thick , and form irregular patches that sometimes measure several centimetres across . initially , the species forms small , disc - shaped fruit bodies through holes in bark , but these expand and merge to form the irregular patches . when fresh , the surface is reminiscent of jelly or wax , and can be smooth or warty , varying in colour from a dull blue to lilac . initially , they are firmly attached to the wood on which they are growing , but as they dry , the edges roll inwards and reveal the dark brown or black underside . the dry specimens have a crusty and slightly fissured surface , and , in colour , are a bright pink or grey , tinted with lilac . there is a relatively thick layer of gelatinous flesh . apart from a brown layer close to the wood , the flesh is hyaline . the species has no distinctive odour or taste , and is inedible . microscopic features peniophora quercina produces spores which take the shape of a curved cylinder ( sausage shaped ) , and have been variously reported as light red , pink and white . they measure from 8 to 12 by 3 to 4 micrometres ( μm ) . the spores are borne on basidia , with four spores per basidium , which measure 50 to 70 by 5 to 12 μm . the species has hyaline cystidia with thick cell walls , which are " heavily encrusted with crystalline material " . the cystidia are often buried within the fruit body as it grows , but can be found in large numbers . they have been variously described as spindle - shaped or conical , and measure 25 to 35 by 10 to 15 μm . the hyphae have clamp connections , and the base of the fruit body is made up of brown hyphae with moderately thick cell walls , measuring 3 to 4 μm in width . similar species peniophora is similar in appearance to p. quercina . however , the edges of the fruit body are highlighted in a dark black , and the species favours ash , as opposed to oak . ecology and distribution peniophora quercina typically grows upon dead wood , which can be attached to the tree or fallen , where it causes white rot . it favours oak , but can also be found on other deciduous trees , such as beech . p. quercina is known to be a pioneer species on dead wood , which means it can be the first species to grow . it is found in europe , where it is very common . though it can be encountered all year , it produces spores in late summer and autumn . it has also been recorded in amur , in eastern asia . the species has also been identified in living sapwood , though it is latent at this time , and it is probable that it waits until the wood begins to die ( when it is drier , but contains more oxygen ) before the mycelia begin to grow . when the species was inoculated into living wood , it did grow , but only around the inoculation wound ; the species did not spread as it would have done on dead wood . another study found that the species actively colonised partially living branches , causing white rot . however , the species had little effect on the cambium , and was mostly limited to the ends of branches .