6 Wood Discoloration

222 8 Habitat of Wood Fungi
Strands (Fig. 8.20d, e): first white, soon brown-black, to 2 mm thick, rootlike,
fragile, black wood beneath the strands; fibers brown, 2–5µm thick,
lumina visible; vessels 10–30µm thick, often deformed, no bars; vegetative
hyphae mostly clampless, rarely with multiple clamps, with brown drops (1–
5µm) holding the hyphal net together.
Coniophora marmorata, Marmoreus cellar fungus
Fruit body: annual, resupinate, pale to olive-brown, grey margin, to 0.4 mm
thick, to 15 cm wide, separable, felty; dimitic; no picture available because not
yet found in buildings in northern Germany;
Strands: brownish, to 1 mm thick, easily separable, no drops.
Coniophora arida,Aridcellarfungus
Fruit body (Fig. 8.20f): annual, resupinate, white-ochre to yellow-brown, light
margin, to 0.3 mm thick, to 10 cm wide, firmly attached, smooth to felty, finefrayed
margin; monomitic;
Strands: rare, white to brown, 0.1 mm thick.
Coniophora olivacea, Olive cellar fungus
Fruit body (Fig. 8.20g): annual, resupinate, olive-brown, margin lighter, fraying
with strands, to 0.6 mm thick, to 6 cm wide, firmly attached, smooth to warty,
fibrous-cottony, septate cystidia, monomitic, partly merging fruit bodies;
Strands: brown, thin.
Significance: The older European literature on occurrence, biology and significance
of the cellar fungi summarizes the several fungi to C. puteana. This
fungus was said to be the most common species in new buildings. It however
occurs also in damp old buildings, on stored wood, timber in soil contact like
poles, piles, sleepers and on bridge timber as well as rarely on stumps and
as wound or a weakness parasite on living trees (Bavendamm 1951a; Grosser
1985; Breitenbach and Kränzlin 1986; Sutter 2003). Of 177 Basidiomycetes
on American mine timbers, 83 isolates were C. puteana (Eslyn and Lombard
1983). In buildings it does not occur, like the name misleadingly suggests,
only in cellars, but it can ascend everywhere on damp timber up to the roof
(Schultze-Dewitz 1985, 1990). Beside softwoods, it attacks also several hardwoods
(Wälchli 1976). As a so-called wet rot fungus (Bravery et al. 2003) with
relatively high requirement for moisture from 30 to about 70% u and the optimum
around 50% (Table 3.6), all timber in the area of damp walls (beam
ends and wall slats), damp floors and ceilings in kitchens, bathrooms and toilets
as well as all timber in areas with water vapor development (swimming
pools, launderettes) is endangered. In vitro, minimum moisture of C. puteana
for wood colonization was 18% u and for decay 22%. The optimum moisture
was broad, from 36 to 210% (Table 8.7). Damage by the cellar fungi is quite
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