Name: Abortiporus biennis
Author: (Bull.) Singer
Citation: Mycologia 36(1): 68 (1944)
Misspellings: Abortiporus bienis
Spores 5-8 × 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.
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 deadwood and a white trunk rot 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 or pale tan; exuding a pinkish juice when squeezed; 2-layered in mature specimens; tough.
Chemical Reactions: KOH negative on flesh.