Though Abortiporus biennis is easily recognized without recourse to a microscope, its microscopic features are distinctive and interesting--from its cystidia to the presence of both spores and chlamydospores (roundish, thick-walled, asexual spores).

The edibility of Abortiporus biennis is unknown, but its flesh is so tough that only a mastodon would be interested.

Description:

Ecology: Saprobic on the wood of hardwoods and occasionally conifers; growing alone or gregariously around the bases of stumps and living trees; causing a white rot in dead wood and a white trunkrot in living wood; summer and fall (winter and spring in warm coastal areas); widely distributed in North America.

Cap: Often covered with the pore surface, but when definable up to 20 cm across; kidney-shaped to semicircular or irregular in outline; whitish to pale brown or reddish brown; sometimes with concentric zones; finely velvety or fairly smooth.

Pore Surface: Whitish, bruising and discoloring reddish or pinkish brown; pores angular to maze-like or irregular, 1-4 per mm; tubes to 6 mm deep.

Stem: Often absent or poorly defined, but when present up to 6 cm long; whitish; velvety.

Flesh: White to pinkish; exuding a pinkish juice when squeezed; 2-layered in mature specimens; tough.

Spore Print: White.

Microscopic Features: Spores 5-8 x 3-5 µ; smooth; broadly elliptical; inamyloid. Chlamydospores round or nearly so; 5-9 µ. Gloeocystidia infrequent to numerous; variously shaped; up to 75 µ long.