6 Wood Discoloration

204 8 Habitat of Wood Fungi
Strands: only rarely on timber in laboratory culture, cream-ochre-dark
brown; fibers to dark brown; no vessels.
Gloeophyllum sepiarium, Yellow-Red Gill Polypore
Fruit body: (Fig. 8.16d, e) annual to perennial, pileate, broadly sessile, dimidiate,
rosette shaped, often imbricate in clusters from a common base or fused
laterally, to 7 cm wide, 12 cm long and 6–8 mm thick, margin slightly wavy;
upper surface when young yellowish brown, then reddish brown and grey to
black when old; scrupose, warted to hispid, finally zonate often differently
colored; hymenophore with straight lamellae (15–20/cm, behind the margin),
edges of lamellae golden brown in active growth, later umber brown, side surface
of lamellae ochre-brown; usually mixed with daedaleoid to sinuous pore
areas (1–2/mm); monstrous fruit bodies in the dark; trimitic; bipolar;
Strands: only rarely on timber in laboratory culture, white-cream; fibers
yellow to brown, no vessels.
Gloeophyllum trabeum, Timber Gill Polypore
Fruit body (Fig. 8.16f, g): annual to perennial, pileate, sessile, imbricate with
several basidiomes from a common base or elongated and fused along wood
cracks, to 3 cm wide, 8 cm long, 8 mm thick; upper surface soft and smooth,
hazelnut to umber brown to grayish when old, weakly zonate to almost azonate,
lighter margin; hymenophore semi-lamellate or labyrinthine to partly poroid
(2–4/mm), rarely lamellate specimens with up to four lamellae/mm along the
margin, ochre to umber brown; monstrous fruit bodies in the dark; dimitic;
bipolar;
Strands: only on timber in laboratory culture, white-beige to yellow-orangegrey
brown, below 1 mm thick; fibers yellow to brown; no vessels.
Significance: predominantly saprobic, G. sepiarium and G. trabeum exceptionally
on living trees; belonging to the strongest brown-rot fungi of coniferous
structural timber; often on stumps; broad moisture optimum (about 40 to
200% u; Table 8.7), on stored timber and on finished timber that is again
moistened, like poles, posts, fences, sleepers and mining timber. The fungi are
the most important destroyers of conifers windows (cf. Fig. 8.17) that had accumulated
moisture due to inappropriate window construction and handling
faults by the user (e.g., injuring of the lacquer layer by nails). For example,
3.5 million (7%) of wooden windows were partly or completely destroyed by
fungi, predominantly by G. abietinum, in Germany between 1955 and 1965
(Seifert 1974). Fungi survive in the sun-warmed and dry window timber due
to their heat and dryness resistance [G. abietinum: 5–7yearssurvivalindry
timber: Theden (1972)]. Fungi cause (by means of substrate mycelium) decay
first only in the wood interior (“interior rot”). The serious brown rot under
the varnish layer is often only recognized if fruit bodies develop. Except on
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