Apple, plane, walnut, whitebeam.
Stem and scaffold limbs (often on or adjacent to wounds) – be certain to look for fallen blackened fruiting bodies around the base of the tree or still attached (sometimes only partly).
Annual. Found growing most often singularly – sometimes in clusters. Fruiting bodies begin a yellow-orange mass and quickly develop into brackets that are brown to orange-gold on the upper surface and a little hairy (hispid). Pore layer light brown. Flesh and tubes brown. Spore yellow (look for spider webs beneath that are stained yellow). Maturing brackets exude yellowish liquid on the underside. Can become quite large. Fruiting bodies blacken in autumn and sometimes fall from the tree. Strip cankers can form at / around sites of fruiting – sometimes in absence of fruiting.
Inonotus cuticularis (frequently observed on beech in similar situations). Neofusicoccum parvum (cankers may look similar – on plane only).
Pathogenic. Can breach reaction zones within its host. Associated with a simultaneous white rot / soft rot. Plane is more resilient against decay, though when combined with soft rot decay caused by Massaria (Splanchnonema platani) branches may be significant weakened. Ash wood can be decayed rapidly. Observed to facilitate in stem and limb failure of the host tree. Associated with woodpecker holes, which may follow / prelude and can indicate the extent of internal decay by this fungus.