The gymnosperms are the only seed-bearing plants of the Pennsylvanian forests, there were no flowering plants in existance. The two common types of gymnosperm fossils found in Kentucky are the pteridosperms (seed ferns) and the cordaites (strap-leafed trees). Early conifers likely existed in Kentucky as well.
The seed fern Alethopteris
The seed ferns grew to small tree size and had leaves similar to the true ferns. The big difference between seed ferns and true ferns is that the seed ferns had seeds, which are sometimes fossilized, and the true ferns had only microscopic spores. The group of plants called seed ferns is extinct, but most of the modern seed-bearing plants descend from them. The leaves (fronds) and seeds of seed ferns are common fossils in the Eastern and Western Kentucky Coal Field and are more common than true-fern fossils.
Cordaite trees (represented by the genus Cordaites) had long strap-like leaves and winged seeds. Fossils of the cordaite limbs, leaves, and seeds are common in some areas of the coal fields. The cordaite plant group is extinct.