Photographs by Andy Newman/

The New York Times

As our Urban Forager, Ava Chin, reminds us, this is high season for mushrooms in the Northeast. And few are faring better this fall than the Disturbing Mushroom of Lincoln Place, a fungus growing in an empty street-tree pit in Park Slope, Brooklyn.

When City Room last reported on the mushroom, a large specimen with the appearance of an old entrail sandwich, in late August, parties unknown had removed it.

Whether they did so because they found it too repugnant to look at or because they believed the reishi’s alleged ability to cure cancer, diabetes and other maladies could withstand the urinary assaults of neighborhood dogs, we do not know.

But like a mycological equivalent of the Prospect Park Lake goose population, the mushroom has proven difficult to exterminate — mushrooms are, after all, only the fruiting bodies of underground networks of mycelia.

The mushroom — identified by several readers as a reishi, the common name of several mushrooms of the genus Ganoderma — has grown back fully. While it no longer packs the same visceral visual wallop, it is bigger than before and is now about the size of a deflated football. Examine the evidence:

July 31 — at its gnarliest:

Photographs by Andy Newman/The New York Times

Aug. 7 — showing its age:

The mushroom was removed sometime between Aug. 7 and Aug. 11.

Sept. 18 — on the rebound:

Oct. 5 — fit as a fiddle:

Now, about the species of mushroom. When Paul Sadowski of the New York Mycological Society identified it in a comment as Ganoderma tsugai or Ganoderma lucidum (two very similar species), he noted that G. lucidum grows on hardwoods while G. tsugai grows on the eastern hemlock.

The parks department tells us that the last inhabitant of that tree pit was a callery pear, which we presume qualifies as a hardwood. On that basis, we are tentatively identifying the mushroom as G. lucidum. But we are not mycologists. Any help out here?