6 Wood Discoloration

Appendix 1 257
22(13,17)
recognizable; vegetative hyphae hyaline, 2–4 µm in diameter, thin-walled,
with clamps; ‘dark fruit bodies’ also antlers-shaped, often with brighter
tips; often in shakes; only on wood (softwoods and hardwoods)
Gloeophyllum trabeum
vegetative hyphae without clamps 23
22∗ vegetative hyphae with clamps, partly with swellings, 1–2 µmindiameter;
fibers and vessels only in older strands; fibers 0.5–2 (−3) µm, hyaline,
straight-lined, thick-walled, septa not visible, no clamps, no reaction in
KOH; vessels 6–40 µm in diameter, thin-walled or slightly thick-walled,
hyaline, vessels in strands surrounded and interwoven by fine hyphae
(0.5–1.5 µm in diameter); mycelium pure white or pink, if being undisturbed
lasting so, easily removable, but sensitive; strands often sunk in
mycelium; on softwoods, rarely on hardwoods; brown rot; genus Oligoporus
and similar fungi (species indistinguishable by strands/mycelia)
e.g., Oligoporus placenta
23(22) arthrospores thin-walled, cylindrical 1.5−2.5 × 5−12 µm; vegetative hyphae
hyaline, thin-walled or slightly thick-walled, 2–3 (−4) µmindiameter,
without clamps, but with primordial clamps; vessels indifferent, septa
present, thin-walled, to 12 µm in diameter; in older parts sometimes small
fibers(comparewith12);myceliumwhitetoyellow,easilyremovable,but
sensitive; strands often sunk in mycelium
monokaryon of Serpula lacrymans
23∗ arthrospores absent or different 34
24(2) setae present, simple setae or stellar setae, within white to cream 25
mycelium, partly only very small nests of setae (search)
24 ∗ setae absent 28
25(24) stellar setae present; vegetative hyphae without clamps 27
25 ∗ setae not clearly stellar-shaped or simply branched, partly rooted 26
26(25) simple, dark-brown, to 180 µm long setae within mycelium, strand and
fruit body; fibers pale yellow, thin-walled, 2–3 µm in diameter, rarely
branched; vegetative hyphae hyaline, 1.5 µm in diameter; mycelium
downy, loam-yellow to brown, also white when young; strand-like structures
up to 4 mm wide and 0.5 mm thick, firmly attached, often fingershaped
branched; usually on hardwoods (often on framework), very rare
on softwoods; so far proven for oak, ash, false acacia, elm, beech, fir and
spruce; white rot Phellinus contiguus
26 ∗ simple, dark-brown setae in fruit bodies and mycelium, under 100 µm;
other species of the genus Phellinus known to occur in buildings (species
not surely distinguishable on the basis of strands/mycelia)
Phellinus nigrolimitatus, P. pini, P. robustus
27(25) stellar setae dichotomously branched, to 90 µm in diameter, in fruit body,
mycelium and strand, partly rare; vegetative hyphae with septa, 2–4 µmin
diameter; strands cream to red-brown, fibrous surface; partly embedded
in white mycelium or fruit body; spores subglobose, smooth; strands on
and in masonry; white rot Asterostroma laxum
27 ∗ stellar setae only rarely branched, up to 190 µm in diameter, in fruit body,
mycelium and strand; vegetative hyphae with septa, 1.5–3 µm indiameter;
strands cream-brown, up to 1 mm in diameter; surface mycelium
www.taq.ir