6 Wood Discoloration

8.3 Tree Rots by Macrofungi 199
dead branches decay upwards and downwards in the stem; white-pocket rot,
preference for latewood of Pinus and Larix (Liese and Schmid 1966; Blanchette
1980), pockets in some hosts concentrated in the earlywood bands (“laminated
rot”, ring shake); occurrence of transpressoria and formation of cavity-shaped
decay pattern (Liese and Schmid 1966); local bark deepenings, outer sapwood
resin-infiltrated (in former times wood used as resinous wood); in spruce,
infection also via sapwood; wood still relatively firm at early decay; dying after
tree felling.
8.3.9
Piptoporus betulinus, Birch Polypore, Birch Conk Fungus
Occurrence: circumboreal, north to Norwegian North Cape at 71 °N (Ryvarden
and Gilbertson 1994); only birch; also in gardens and parks;
Fruit body (Fig. 8.15f): annual (summer to late autumn), but enduring;
solitary and in groups; shell-shaped, fan-like brackets (8–30cm); pilei pendent,
dimidiate, or reniform; often several meters high on the stem; upper surface:
dull-smooth, unzonate, young cream-white, later ochre-brown to grey-brown,
old usually cracked; pore surface: white to cream-brownish circular to angular
pores (3–5/mm); dimitic; some isolates bipolar (Stalpers 1978); fruit body
previously used in Fennoscandia as a cushion for knives, which do not rust
while standing in the fruit body;
Significance: weakness-parasite, host-specific on older and weakened (e.g.,
lack of light) birch; infection via wounds (branch breakage); brown rot; danger
of windthrow.
8.3.10
Polyporus squamosus, Scaly Polypore
Occurrence: circumpolar in Europe (north to Finnmark at 70 °N), Australia,
Asia, and America; hardwoods such as ash, beech, elm, horse chestnut, lime,
maple, planetree, poplar, and willow (Schwarze 2005); frequently on urban and
park trees;
Fruit body (Fig. 8.15g): annual (early summer); solitary or in groups from
a branched base; usually laterally stipitate, with circle to fan-like cap (to 80 cm
wide and 2 kg fresh weight); upper surface: yellow-ochre with concentrically
arranged light to dark-brown, scale-like patches, smooth and sticky; pore
surface: cream-yellowish with angular-oval pores (1–2/mm); whitish stipe (up
to 10 cm) at the basis dark-brown to black-felty; dimitic; tetrapolar (Stalpers
1978); young edible;
Significance: white rot in the heartwood of living and dead hardwoods with
black demarcation lines after penetration through wounds.
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