6 Wood Discoloration

214 8 Habitat of Wood Fungi
8.5.2.3
Dacrymyces stillatus, Orange Jelly
Fruit body (Fig. 8.18f, g): yellow-orange-red, also whitish, dark orange when
dry, button-shaped, lenticular to mug- or plate-like, 1–15 mm wide, gelatinouselastic,slimy
meltingwhenold,solitary andingroups,oftentwodifferentforms
on the same place, a brighter form with basidiospores and a darker form with
arthrospores, often appearing through paint;
Significance: white rot, softwoods and hardwoods, wood darkens, decay
commonly patchy with small pockets of rot, often restricted to interior of
timber, on window and doorframes, common outdoors on windows, claddings
and along the gable board of the roof (Alfredsen et al. 2005).
8.5.3
Common House-Rot Fungi
There is a bulk of knowledge on the common indoor wood decay fungi due
to their economic importance. Thus, these species and species groups are
described in more detail in the following (also Findlay 1967; Bavendamm
1969; Coggins 1980; Cockcroft 1981; Grosser 1985; Jennings and Bravery 1991;
Ryvarden and Gilbertson 1993, 1994; Krieglsteiner 2000; Weiß et al. 2000;
Kempe 2003; Sutter 2003; Huckfeldt and Schmidt 2005).
8.5.3.1
Donkioporia expansa, Oak Polypore
This fungus is only recognized since the 1920s as relevant for practice and
since about 1985 as important decay fungus in buildings (Kleist and Seehann
1999; Erler 2005). Assumably, the species was often overlooked despite the less
common decay type of a white rot in buildings and the large size of its fruit
bodies. A reason it was overlooked may be that damage is often restricted to
wood interior and not noticed until fruit bodies appear and furthermore that
the fruit bodies are inconspicuously embedded in plentiful surface mycelium.
Occurrence: fairly rare, Central Europe, North America, in Germany preferentially
in the south, at least in Europe almost exclusively restricted to structural
timber, preferably Quercus, but also Castanea, Fraxinus, Populus and
Prunus,frequentlyalsoonindoortimberofPicea and Pinus;
Fruit body (Fig. 8.19a, b): perennial, resupinate, first white, then ochre to
reddish-tobacco-brown to grey with ageing, to 10 cm thick, becoming widely
effused to a few square meters, firmly attached, an walls wavy to stairs-like,
often multi-layered, tough-elastic with silvery surface when fresh, hard and
brittle when dry, easily separable when old, mainly made up of long tubes, 4–5
www.taq.ir