Brown cubical pocket rot

Brown cubical pocket rot - Fruiting bodies of <em>Veluticeps fimbriata</em> on a fallen western hemlock log
  • Latin name: Veluticeps fimbriata (Ellis & Everh.) Nakas.
  • French name: Carie brune cubique alvéolaire
  • Division: Basidiomycota
  • Class: Aphyllophorales
  • Synonym(s): Hymenochaete fimbriata (Ellis & Everh.),
    Stereum rugisporum (Ellis & Everh.) Burt
Description

Micro-habitat(s)

Trunk

Distribution

British Columbia, North America

This fungus is widely distributed throughout the range of its hosts in B.C.

Damage, symptoms and biology

Veluticeps fimbriata was once considered to be only a slash destroyer, but is now recognized as a commonly occurring trunk rot in conifers. The fungus is also capable of continued development in unseasoned timber.

The early stage of decay is characterized by a wet, dark brown or black stain that occurs in streaks or patches. The advanced stage develops in pockets surrounded by what appears to be sound wood. In the final stage the individual pockets coalesce, forming an almost continuous column of decay. The decay is soft and friable and is often associated with dark stain, a thin cobweb-like accumulation of mycelium and an odour resembling that of stored apples.

The perennial fruiting bodies are small and resupinate or shelf-like with a roughened grey to light brown lower surface and a dark brown to nearly black upper surface. The context is brown. The hymenial surface is smooth to warted, and usually cracked to some extent. Fruiting bodies may form on the scarred faces of living trees but more frequently are found on old logs and dead material on the ground.

Other information

Collections of this fungus were previously identified as Columnocystis abietina (= Stereum abietinum Pers.), but a recent taxonomic study by Nakasone (1990) has split the group, and treats the collections from B.C. as V. fimbriata.

Microscopic Characteristics:

Contextual hyphae in five distinct layers, clamp connections present. Basidiospores ellipsoid to cylindrical, hyaline, but occasionally pale yellow, slightly thick-walled, smooth, IKI-, 11.9-15.5 x 4.7-5.6(-6) µm. Growth in culture very slow, mat becoming brown, reverse brown, conspicuous opaque brown dots in agar, laccase negative, simple septa, globose to oblong chlamydospores. Stalpers: (1) 2 (9) (10) (11) 13 (14) (16) 17 (21) 22 (30) (31) 34 38 (39) (40) 42 45 48 (49) (50) 52 53 (54) (60) 61 67 (72) 75 80 83 85 90 96 98.

Canadian Forest Service Publications

Brown cubical pocket rot

Information on host(s)

In B.C., Veluticeps fimbriata has been reported mainly on western hemlock, amabilis, grand, and subalpine fir, but also on mountain hemlock, Douglas-fir, and Engelmann and Sitka spruce. In other parts of North America it has also been found on western redcedar, white and black spruce, western larch, and pine.

Main host(s)

Amabilis fir, black spruce, Engelmann spruce, grand fir, mountain hemlock, Rocky Mountain Douglas-fir, Sitka spruce, subalpine fir, western hemlock, western larch, western redcedar, white spruce

Photos
  • Brown cubical pocket rot Fruiting bodies of Veluticeps fimbriata on a fallen western hemlock log
  • Brown cubical pocket rot Advanced decay of western hemlock caused by V. fimbriata
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