Habitat/range: On hardwoods, causing a brown rot. In BC, known from two collections on southern Vancouver Island: one at Observatory Hill, Victoria, and the other on Arbutus menziesii at Metchosin. Elsewhere in western North America, known from AB, WA, MT, WY, and AZ.Basidiomata effuse, reflexed, rarely sessile, typically annual, tough to corky, separable; pileus typically elongated and projecting up to 1.5 cm out from the substrate, some nodulose, some imbricate; pileus surface pale brown aging to greyish brown to blackish brown, finely tomentose in aging to tufted then glabrous; context pale yellowish brown, 1–2 mm thick; tubes pale yellow-
ish brown or paler, up to 5 mm deep; margin distinct, sharp to rounded; pore surface pale cinnamon to pale brown; pores round, angular or sinuous, 2–4 per millimetre, some labyrinth-like, up to 4 mm long and 1 mm wide.
Generative hyphae 2–4 μm diameter, walls thin to slightly thick; skeletal hyphae predominate in the context, 2–5 μm diameter; binding hyphae rare, confined to the context, 2–3 μm diameter; basidiospores cylindrical, ellip- soid to broadly ellipsoid, 7–10 × 2.5–4.0 μm, typically slightly concave on the surface above the apiculus.
Notes: The pale brown colour distinguishes A. malicola from the other Antro- dia species in British Columbia, except A. serialis is brownish yellow. Micro- scopically, in the context the rare hypha is frequently branched and these are interpreted as binding hyphae.