My friend Shamalama (username on The Fossil Forum website) sent me some pictures of recent finds from St. Clair, Pennsylvania. These plants grew in the Late Carboniferous or Pennsylvanian Period and can be found in the Llewellyn Formation.
St. Clair is famous for the white appearance of their plant fossils which caused by aluminum silicate or pyrophyllite. This first fossil is Alethopteris.
This second fossil is a Asterophyllites. It could be of the species Asterophyllites charaeformis.
This next fossil is a Sphenophyllum.
This last fossil plant is unidentified.