Species belonging to the Carboniferous genera Lepidodendron and Lepidophloios are well known from the coalfields of Pennsylvania (Lower Asturian (Westphalian D) substage of the Pennsylvanian) through the publications of Lesquereux and White. They believed that the lycophyte flora was rather distinct from other contemporaneous coal floras elsewhere due to its isolation. A full revision of the lepidodendroid lycophyte species is given here and this reassessment permitted comparisons with those floras known from the European and Canadian Maritimes coalfields. Differences in species distribution suggest there was a barrier (Arcadian Highlands) to species distribution to and from the coalfields of Pennsylvania. Several species are recognized only from the coalfields of Pennsylvania, although the number has been significantly reduced from the original publications.