This fungus may show itself in two forms.
(1) The fruitbody is a shelf-like growth, with pores on the underside (each pore being the mouth of a short tube). This is a fairly common form of polypore growth. The upper surface is white to reddish-brown, may show some radial ridging and is smooth or velvety in feel. The pores are angular or somewhat maze-like and white to pinkish-brown. The fruitbody may grow from a stump or at times seemingly from the soil (but in such cases it has arisen from buried wood). Fruitbodies often grow in clusters with some overlapping others and, when on the ground, may be arranged circularly so as to give the whole cluster a rosette-like appearance.
(2) The fruitbody is highly irregular in shape, with no distinct upper and lower sides and with tiny cavities covering the entire surface.
Sometimes you see elements of both (1) and (2) combined.
It would be hard to confuse a type (2) fruitbody with anything else. A rosette of type (1) fruitbodies appearing in say a lawn would be hard to mistake for anything else but such fruitbodies appearing as shelves from a stump could be mistaken for more than one other genus, so an identification from photographs may not be possible.
Abortiporus biennis is listed in the following regions: