Home / Polypores, brackets & crusts / TM0001
Perennial polypore on an oak trunk
Ganoderma sp. Genus
Angles captured. Two close frames of the large white surface, one of the shelving brackets below and to the side, and one standing back to show the whole tree.
Morphology
A large bracket, 25–30 cm across, growing straight out of a cavity at the base of a living oak. The face toward the camera is thick, waxy and pure chalk-white, with a heavy rolled margin and a deeply lobed, almost scalloped outline — this is a young, actively growing pore surface. A patch near the upper left is finely pitted where the pores are already forming. A second frame shows older, shelving, concentrically banded brackets in grey-brown at the same cavity, below and behind the white one.
Habitat & substrate
Emerging from a wound cavity at the base of a large living oak, moss on the surrounding bark. Parasitic or heart-rotting on living hardwood.
Lookalikes & what rules them out
The combination of a brown zonate upper surface on old brackets and a thick soft white pore surface on new growth is characteristic of the Ganoderma applanatum group — the artist's conk. Fomitopsis and Rigidoporus are alternatives but the layered perennial habit here fits Ganoderma.
To confirm this identification
Scratch the white surface with a fingertip or twig. An artist's conk bruises instantly and permanently dark brown, and the mark persists — which is the origin of the common name. It is among the most definitive field tests available.
Notes
The largest single fruitbody anywhere in the guide, and the only perennial one. Worth revisiting the same tree annually — Ganoderma adds a new pore layer each year and the bracket will keep growing.
Found at Massasoit Rd area, Worcester, MA on Friday, 10 October 2025 at 16:17. See the full walk for that day's weather and everything else recorded.
Others in this group
Small zoned bracketTrametes or Stereum · Jul 31Moderate
Cinnabar polypore on oakPycnoporus cinnabarinus (= Trametes cinnabarina) · Aug 1High
Zoned brackets on rockTrametes or Stereum · Aug 6Moderate
Birch polyporeFomitopsis betulina or Fomes fomentarius · Aug 6Moderate
Cinnabar polypore on a stickPycnoporus cinnabarinus (= Trametes cinnabarina) · Aug 6High
Bracket colony among fernsTrametes or Stereum · Aug 8Low–moderate
Turkey tail on the fallen logTrametes versicolor · Aug 8Moderate–high
Bracket colony on the rock ledgeTrametes or Stereum · Aug 8Low–moderate