Spiculosa canker, caused by _Poria spiculosa_, is found on bottomland
oaks in the South. Occasionally this disease will also degrade hickories
and honeylocust.
[Illustration: Fruiting body of Poria rot and canker on oak.]
[Illustration: Cross section of tree showing rot and decay.]
Spiculosa canker is considered to be a canker-rot disease, a type of
decay in which the causal organism incites not only heart-rot but also
large irregular cankers. Infected trees have cankers that appear as
rough circular swellings on the bole. The canker centers are depressed
and old branch stubs are discernible. Fungus fruiting bodies, or conks,
usually are not present on living trees but develop on snags or decayed
logs. The conks grow flat under the bark and push it off to expose the
brown fungus fruiting surface.
Control for Spiculosa canker is similar to other canker rots: salvage to
remove undesirable cankered trees that may be later replaced by better
quality trees.