Psaronius was a
Marattialean tree fern which grew to 10m in height, and is associated with leaves of the
organ genus Pecopteris and other extinct tree ferns. Originally,
Psaronius was a name for the petrified stems, but today the genus is used for the entire tree fern.
Psaronius tree fern fossils are found from the Carboniferous through the Permian.