Epithet = loving Robinia (black locust). Genus = perennial pored.
Descriptions don't say whether it is annual or perennial. The one outside the Field Museum could be said to be perennial as the second year growth surrounded the lower part and extended upon the first year growth. But the second year pore layer was separated by a large amount of context from the first year pore layer above it.
The other pileate Perenniporia have a more colored upper surface, or develop a dark crust, or are much thinner or smaller.
Heart rot of hardwoods. Typically on Robinia (locust) but Overbolts reported that it seemingly was best developed on Celtis (hackberry).
Perennial brackets can be found year-round.
Widespread across eastern North America. This is an American species not seen in Europe. Ryvarden (1983) reported it for India and Pakistan. It is on a 2012 checklist of the polypores from Liaoning Province, China.
Chicago Region status
Rare. There are no known historic records for Chicago. Elsewhere in Illinois it was found in Coles County and Pope County. In 2018 we found it in Putnam County at the Dixon Waterfowl Refuge Bioblitz.
Our first Chicago record was on old-growth hackberry (Celtis) outside the east door of the Field Museum. Leacock collected it in 2013 but did not identify it until it was better developed in 2014 and recollected. It became more extensive on the base of the tree in 2015, and then fruited in more places on base of trunk in 2016. In summer 2016 the tree was noticeably stressed with the foliage thinner in the crown and the leaves paler green than the neighbouring hackberry trees. In early August the city removed all but the trunk (prior to Aug 12). Patrick made another collection; the fresh brackets failed to give a spore print. Coincidently, this was the same week that Michael Kuo posted his web page on this species (photos of Patrick with the fungus at Kuo link below). The city then removed the trunk and upper roots. Fairly soon after saprobic agarics appeared there.
An additional specimen was identified recently (Dec. 2017): found September 2008, also on hackberry, about 3200 South Lake Shore Drive.
First record was P.R. Leacock 11105 (November 2013); repeated collections with the last being PRL 13046 (August 2016).
Collected at Falls Church, Virginia, on decayed spots in living trunks of Robinia pseudoacacia (black locust), July 11, 1904, W. A. Murrill. [but the NY photo of the type specimen label shows "Aug. 1901"]
Index Fungorum (as of 2017) is in error listing the current name as Trametes.